The development of the perception of ambiguity

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The development of the perception of ambiguity
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Mederer, Hyta, 1949-
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Language acquisition   ( lcsh )
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Thesis--University of Florida.
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Includes bibliographical references (leaf 113).
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by Hyta Mederer.
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Typescript.
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Vita.

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THE DEVELOPMENT OF THE PERCEPTION
OF AMBIGUITY





BY

HYTA MEDERER


A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL
OF THE UNIVERSITY OF FLORIDA IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY



UNIVERSITY OF FLORIDA


1979








































Copyright 1979

by

Hyta Mederer



































For Phil--the closer the better














ACKNOWLEDGMENTS


I would like to express my appreciation to Dr. Robert

Scholes for his many contributions to this dissertation,

including his suggestions for the test designs, for the

analyses, and for the pictures, as well as his patience

in directing its progress.

I would also like to express my gratitude to Dr. Jean

Casagrande both for his comments and suggestions concerning

this dissertation and for his support and understanding

throughout my enrollment at the University of Florida.

To Dr. Paul Kotey I would like to convey my appreciation

for his reading and commenting on my dissertation as well

as for his support and advice.

I would like to thank Dr. Ira Fischler for his thorough

reading of this dissertation and for his invaluable sugges-

tions for its improvement.

To Dr. Tom Doherty I wish to express my sincere grati-

tude for his many hours of help in the analysis and inter-

pretation of the data for Experiment VI.

I would finally like to thank Steve Sledjeski of P.K.

Yonge Laboratory School for making it possible for me to

test students at that school and for providing me with

ideal testing conditions.










TABLE OF CONTENTS


ACKNOWLEDGMENTS . .

LIST OF TABLES. . .

LIST OF FIGURES . .

ABSTRACT. . .

CHAPTER I INTRODUCTION .


Notes. . .

CHAPTER II EXPERIMENTS I THROUGH V .

Experiment I . .
Experiment II. . .
Experiment III . .
Experiment IV. . .
Experiment V . .
Discussion of Experiments I Through V.

CHAPTER III EXPERIMENT VI. .


Method . .
Procedure. . .
Results. . .

CHAPTER IV DISCUSSION. . .

CHAPTER V CONCLUSION . .

APPENDIX A SENTENCES FOR EXPERIMENT I. .

APPENDIX B SENTENCES FOR EXPERIMENT IV .

APPENDIX C PICTURES FOR EXPERIMENTS I THR

APPENDIX D SENTENCES FOR EXPERIMENT VI .

REFERENCES. . .

BIOGRAPHICAL SKETCH . .


. 47
. 48
. 50

. 69

. 89

. 91

. 93

OUGH V. 96

. 111

. 113

. 114


Page

. . iv

. . vi

. . vii

. . viii

. . 1













LIST OF TABLES


Table


1 Mean Number of Choices of Two Pictures for
the Ambiguous Sentences. . .

2 Mean Number of Choices of Two Pictures for
the Unambiguous Sentences. . .

3 Percent of Incorrect Responses on the Four
Verb Forms by Male and Female Subjects .

4 Percent of Incorrect Responses on Subject
and Object Nominals by Male and Female Subjects.

5 Percent of Choices of Are and Look in the
Ambiguous Sentences. . .

6 Percent of Choices of Plural Verb Forms in
the Ambiguous Sentences by Male and Female
Subjects . . .

7 Percent of Incorrect Responses for the Main
Verbs Be and Look. . .

8 Percent of Incorrect Responses on Subject
and Object Nominals. . .

9 Percent of Choices of Plural Verb Forms in
the Ambiguous Sentences. . .


Page


. 66


* 73

77


. 80


: :














LIST OF FIGURES


Page

Figure 1 Percent of incorrect responses for the
verb form Is by male and female subjects. 54

Figure 2 Percent of incorrect responses for the
verb form Are by male and female subjects 55

Figure 3 Percent of incorrect responses for the
verb form Looks by male and female subjects 56

Figure 4 Percent of incorrect responses for the
verb form Look by male and female subjects. 57

Figure 5 Percent of incorrect responses on subject
and object nominals by male and female
subjects. . . 61

Figure 6 Percent of choices of Are and Look in
the ambiguous sentences . 64

Figure 7 Percent of choices of plural verb forms
in the ambiguous sentences by male and
female subjects . . 67

Figure 8 Percent of incorrect responses for the
main verbs Be and Look. . ... 74

Figure 9 Percent of incorrect responses on subject
and object nominals . 78

Figure 10 Percent of choices of plural verb forms
in the ambiguous sentences. . ... 81


vii













Abstract of Dissertation Presented to the Graduate Council
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy



THE DEVELOPMENT OF THE PERCEPTION
OF AMBIGUITY

By

Hyta Mederer

December, 1979

Chairman: Dr. Robert J. Scholes
Major Department: Linguistics


Sixty-nine white, native-English speakers between the

ages of eight and twelve years old were tested through picture-

verification in five related designs to determine at what age

they could perceive deep-structure ambiguity. The subjects

heard ten ambiguous sentences and twenty unambiguous sentences.

The unambiguous sentences consisted of two sentences for each

ambiguous sentence, each conveying one of the meanings of the

ambiguous sentence. Subjects chose pictures to indicate which

meanings they perceived. It was expected that the subjects

would choose one picture for each unambiguous sentence and,

when they perceived the ambiguity, choose two pictures for the

ambiguous sentences. However, the subjects consistently chose

more than one picture for both the ambiguous and unambiguous

sentences, indicating that to them all of the sentences were

ambiguous.


viii










Because most of the test sentences were composed of a

derived nominal, some form of the verb be, and an adjective,

it was felt that the problems were related either to the

verb be, itself, or to the plural marker which disambiguated

the nominal. A second test was designed in which twenty-four

sentences, twelve ambiguous and twelve unambiguous, were pre-

sented to 130 subjects between the ages of 7 and 12, and to

53 subjects between 18 and 29. These sentences consisted of

an ambiguous nominal, a subject nominal, or an object nominal

followed by either is and are or looks and look followed by an

adjective. The subjects were asked to circle the correct form

of the verb. For the ambiguous sentences, either form was

correct. For the subject nominal the plural form was correct,

and for the object nominal the singular form was correct. It

was concluded that subject/verb agreement in the context of

derived nominals is not fully acquired by the age of 12 years.

This finding was presented as an explanation for the inability

of the subjects in the first experiment to disambiguate the

nominal and thus perceive that twenty of the original test

sentences were unambiguous.












CHAPTER I

INTRODUCTION


Attempts to understand how a child learns to speak his

native language have produced numerous anecdotal descriptions

of the child's linguistic behavior. However, systematic

descriptions of the child's acquisition processes are still

quite limited. We know the sequences of certain elements as

they appear during the first five years of the child's life.

But as the child grows older, he gains more subtle aspects of

his language. These more subtle aspects include various com-

plexities of sentence structure which the child learns to

comprehend and produce. The relationship between two sentences

which are similar in meaning and in structure can be described

with the use of transformations within the context of Trans-

formational Grammar. The Passive Transformation, for example,

states the structural relationship between sentences l.a. and

l.b.

l.a. Sam Peckinpah directed that movie.

l.b. That movie was directed by Sam Peckinpah.

Although these sentences share basically the same meaning,

their structures are quite different. As part of the process

of acquiring language, a child must learn those things about

sentence structure which transformations explain. Through

various testing methods, we are able to determine that by a

certain age most normal children have a specific transformation









in their grammars. For example, by the age of nine years

most children have acquired Dative Movement, a rule which

allows the child to comprehend that sentences l.c. and l.d.

have the same meaning (Scholes, Tanis, and Turner 1976).

l.c. Tom showed the dog to the little boy.

l.d. Tom showed the little boy the dog.

The number of grammatical structures which a child must

acquire is quite large, but the number for which we know the

age of acquisition is quite small. It is important that we

be able to say when a certain structure is acquired.

One reason for this importance is that this information

provides a guideline for comparing languages. We know that

native speakers of English acquire transformations in a fixed

sequence. Presumably there is a fixed sequence for each

language. Although different languages employ a variety of

different rules, there is an overlap in their use. For

example, many languages employ a plural marker to indicate

that there is a difference between nouns in the singular and

nouns in the plural. The native English-speaking child

acquires the plural morpheme by the age of four years. The

speakers of Egyptian Arabic do not master the rules of plural

formation before the age of fifteen years (Omar 1970, quoted

in Slobin 1973). Such a comparison offers us insight into

the similarities and differences which exist among languages.

Obviously, in this case there is a vast difference in the

complexity of the rules for plural formation in English and









those for Egyptian Arabic. If enough information about the

acquisitional sequences for different languages were available,

it would be possible to determine whether there is a trend

across languages toward a universal sequence of acquisition.

Secondly, because language development is highly corre-

lated with intellectual development, a knowledge of the order

and age of acquisition of transformations would provide a

basis for determining a child's developmental progress. This

is true among normal children, but it would also give us a

reference point for studying people who are deaf or retarded

or brain-damaged or who have undergone a hemispherectomy or

are abnormal in some other respect which is related to lin-

guistic development.

For those people who believe that the dissolution of

language (as with aphasia) follows somewhat the reverse order

of language acquisition, the knowledge of this sequence would

improve the chances for proving or disproving this belief.

A fourth reason for knowing the age of acquisition of

certain transformations is that for people who design tests

such as reading and IQ tests, it would be far more consistent

to test children's abilities in those areas of which they are

able to comprehend the content. In other words, a child may

perform poorly on a test because he does not understand the

syntax in the instructions or in some material which he has

to read. Consequently, it may appear that the child cannot

perform a particular task when, in fact, he may be quite










capable, but he simply does not comprehend other information

that he needs in order to complete the task. The problem is

not limited to children. A student may be asked to read an

article and then to draw a particular conclusion. He may

reach the wrong conclusion, not because of faulty logic or

because of an inability to read, but rather because the syntax

of the article is too complex for him.

A specific example has occurred in the Writing Labora-

tory at the University of Florida.2 Students in the Writing

Laboratory are tested in their ability to recognize sentence

errors. On one test the students were instructed to find

the incorrect sentence from a group of three sentences. The

following sentences are two of a set of three sentences from

this test:

l.e. A wide range of choices is offered students by

educators experimenting with new programs.

l.f. Experimenting with new programs, a wide range of

choices is offered college students.


Sentence l.f. is considered grammatically incorrect because

the introductory clause is a so-called 'dangling modifier.'

However, sentence l.e., although technically correct, is

syntactically difficult to the students in the Writing Labora-

tory. The first clause is passive, the to which is the overt

marker of the dative has been deleted, and the indication

that experimenting is derived from a relative clause is also

missing. This syntactic complexity led many of the students

to choose sentence l.e. as the incorrect sentence.










On another test in the Writing Laboratory the students

were instructed to identify the errors in the sentences on

the test. They were told that there would be either sentence

fragments, run-on sentences, sentences which lack parallel

structure, or sentences with no errors. One of the items on

the test is listed here as l.g.

l.g. Although the life-support system was defective,

the problem was discovered too late. Fearing money for the

space program will end if there is a scandal.


The clause 'Fearing money for the space program will end if

there is a scandal' is a sentence fragment. Many of the stu-

dents in the Writing Laboratory had considerable trouble with

this item on the test because it made absolutely no sense to

them. One student claimed that the clause was a complete

sentence with fearing money as the subject of the verb will

end rather than money as the subject of will end. From a

purely syntactic point of view, this interpretation is

possible. However, no sentence content corresponds to such

a syntactic structure, a fact which did not bother the student

because she was unable to make sense out of it in any other

way. The meaning of this clause would have been much clearer

had there been a that complementizer between fearing and money.

Adding that would not have altered the fact that this clause

is a sentence fragment, but it would have helped the students

in their understanding of this item. The point is that the

students' performance on this item was meant to indicate that










they could not recognize sentence fragments, when, in fact,

the problem was one of unnecessarily complex syntax. Had

syntactic complexity been taken into consideration, the test

would have been more valid. This sort of problem should be

avoided by people who design tests.

If it is in fact the case that different dialects of the

same language have different rules or different ordering of

rules or that their speakers acquire some transformations in

different orders, then this information would be important

for the following reasons:

1. As a basis for descriptive comparison.

2. If transformation X is acquired at the age of 7 in

one dialect, but not until the age of 9 in another

dialect, then this should be recognized as a dialect

difference and not, for example, as an indication of

retardation.

3. Aphasics of one dialect may possibly produce different

behavior from aphasics of another dialect; that is,

dissolution might follow a different sequence de-

pending on the aphasic's dialect.

4. Tests should be designed so as to avoid a bias in

favor of or against a particular dialect.

These four reasons are the same as the first four major rea-

sons but are applied here specifically to dialects.

Finding the age of acquisition of particular abilities

is simply one more aspect of the challenge that Noam Chomsky









set forth when he said, 'As a long-range task for general

linguistics, we might set the problem of developing an account

of this innate linguistic theory that provides a basis for

language learning' (1965:25). And an understanding or knowl-

edge of 'this innate linguistic theory' which a child uses

in order to acquire his native language would provide a fur-

ther understanding of the relationship of language to other

mental faculties. An understanding of the nature of the

child's internal grammar would provide a view into other

aspects of the mind. Since, as Chomsky put it, 'An actual

language may result only from the interaction of several

mental faculties, one being the faculty of language' (1975:

43), an increase in the understanding of one offers better

understanding of others.

It is for these reasons that we continue to search for a

systematic description of the processes which are involved in

language acquisition.

With these ideas in mind, I set out to determine at what

age the normal, white, native English-speaking child acquires

the ability to perceive that a sentence is ambiguous at the

level of the deep structure. Ambiguity, the presence of more

than one meaning, is generally divided into three main cate-

gories.

1. Lexical ambiguity--when a single word or lexical item

has more than one meaning. In the sentence 'The young boy was

sitting by the bank' the word bank may mean either a building

where people keep money or it may mean the edge of a river.









2. Surface-structure ambiguity--when different meanings

can result depending on the way in which the words in the sen-

tence are grouped. Surface-structure ambiguity, also known as

surface-bracketing ambiguity, is defined by Fodor, Bever, and

Garrett (1974:95) as ambiguity for which there are 'alternative

constituent structure analyses.' For example, the meaning of

the sentence 'They are visiting relatives' depends on whether

the words are visiting are grouped as a single constituent or

whether the words visiting relatives are grouped as a single

constituent. The meanings of this sentence 'can be represented

by reference to alternative bracketings' (Fodor, Bever, Garrett

1974:95) of the elements of the sentence:

l.h. They (are visiting) relatives.

l.i. They are (visiting relatives).

3. Deep-structure ambiguity--when two different deep

structures undergo transformations which give them identical

surface structures. It is not possible to bracket constituents

of sentences which are ambiguous at the deep-structure level

in order to represent the differences in structure or meaning.

Consider the sentence 'The police stopped drinking on campus.'

In this sentence, it is the subject of drinking which is am-

biguous. In the deep structure there are different subjects

for drinking, but in the surface structure those subjects have

been deleted by transformations. For the meaning which is

equivalent to 'The police quit drinking on campus,' the sub-

ject of drinking was deleted by Equivalent Noun Phrase

Deletion Transformation (also known as Equi NP Deletion or,










simply, as Equi). This transformation applies when the subject

of the main clause is also the subject of a gerund or an in-

finitive. It functions to delete the subject of that gerund

or infinitive. For the meaning which is equivalent to 'The

police ended drinking on campus,' the subject was deleted by

Pro Deletion Transformation. This transformation applies when

the subject of a gerund or an infinitive is an unspecified NP

in the deep structure. Its function is to delete the subject

of that infinitive or gerund.

A behavioral difference between surface-structure am-

biguities and deep-structure ambiguities is that for the for-

mer there is a difference in intonation patterns depending on

the meaning, whereas, for the latter, the intonation pattern

remains constant regardless of meaning. The sentence 'They

are flying planes' is a surface-structure ambiguity because

it can be explained in terms of bracketing:

l.j. They (are flying) planes.

l.k. They are (flying planes).

Such a sentence can be disambiguated with an intonation pattern

comparable to the bracketing:

1.1. They are flying planes.

l.m. They are flying planes.

However, a sentence such as 'They want to stop smoking' cannot

be disambiguated through an intonation pattern. In order for

a person to perceive both meanings of a deep-structure ambiguity,

he must be able to comprehend the structures which correspond

to each meaning. In the case of 'They want to stop smoking,'










the structure which corresponds to 'They want to quit smoking'

in which they is the subject of smoking is derived through

Equi NP Deletion. The ability to comprehend this particular

meaning depends on the ability to understand a structure which

is produced through Equi NP Deletion Transformation. Similarly,

the structure which corresponds to 'They want to prevent

smoking,' in which the subject of smoking is an unidentified

or unspecified element comparable to someone or others, has

been derived through Pro Deletion Transformation. The com-

prehension of this meaning is contingent on the ability to

understand the structure of a sentence which is derived through

Pro Deletion Transformation. Consequently, the ability to

perceive the ambiguity of this sentence is based on the ability

to comprehend the structures for both meanings. Thus a child

could not perceive both meanings of a deep-structure ambiguity

unless he had acquired both transformations which are necessary

for the two meanings.

The age at which a child becomes capable of perceiving

deep-structure ambiguity should be predictable on the basis

of the age of acquisition of the transformations which are

required to generate the structures that correspond to both

meanings. For example, if a child acquires the ability to

comprehend Equi NP Deletion Transformation by the age of 4

years, but acquires Pro Deletion Transformation at the age of

9 years, then beginning only at the age of 9 years should he

be able to perceive the ambiguity of a sentence such as 'They

want to stop smoking.' This prediction is based on the










assumption that perception of deep-structure ambiguity is

determined by the ability to comprehend relevant transforma-

tions and by cognitive capacities that are developed prior to

or at the same time as these transformations. If any such

cognitive capacities are necessary for the perception of am-

biguity but have not been developed by the time that these

relevant transformations are acquired, then the transformations,

themselves, would not be sufficient for the perception of the

ambiguity.

The assumption that the perception of deep-structure am-

biguity is determined by the ability to comprehend the relevant

transformations was the subject of this investigation. The

only other study which has investigated ambiguity from a

developmental standpoint was done by Frank Kessel (1970).

Kessel tested fifty children from kindergarten through fifth

grade (with the exception of the fourth grade) in their ability

to perceive lexical ambiguity, surface-structure ambiguity,

and deep-structure ambiguity.

In his study, subjects were asked to choose the picture

or pictures which represented the sentences which the experi-

menter read. The subjects heard twelve sentences, four for

each type of ambiguity. The four sentences with deep-structure

ambiguity which Kessel presented to his subjects were:

l.n. The eating of the chicken was sloppy.

l.o. She hit the man with glasses.

l.p. The visiting of the doctor was happening.

l.q. The shooting of the soldier was bad. (p. 26)






12



Kessel found that 'only after the age of 10 do children con-

sistently and spontaneously (without "lead-in" questions)

detect both meanings in surface and underlying structure am-

biguities' (p. 43). He made no attempt to determine or explain

what factors contribute to the acquisition of the ability to

perceive ambiguity.








Notes

1Whether a child actually acquires transformations or
whether transformations are, more appropriately, devices to
describe linguistic facts is still up for debate. For the
purpose of this paper, when I discuss the processes involved
in 'acquiring a transformation,' I am aware of the problems
which this phrase implies, but I will use this terminology for
the sake of simplicity.

2The Writing Laboratory is a one-credit course offered by
the Reading and Writing Center at the University of Florida.
It is designed to help students with such basic writing skills
as paragraph development and grammar.

3These examples are used by permission of The Writing
Laboratory. The tests from which these sentences were taken
are not professionally designed, standardized tests. They
were, instead, written within the Writing Laboratory of the
University of Florida and, like any tests which are designed
by a classroom teacher, are likely to contain errors in validity
and reliability.











CHAPTER II

EXPERIMENTS THROUGH V


Unlike Kessel's study, this investigation attempted to

predict perception of deep-structure ambiguity on the basis

of linguistic theory of transformations. This study attempted

to show that a child's ability to detect deep-structure am-

biguity can be predicted by his ability to handle certain

transformations. Only after a child has acquired the trans-

formations which are necessary to generate both meanings of

an ambiguous sentence, should he be able to comprehend both

meanings of that sentence.

This hypothesis was tested by presenting students with

sentences which were ambiguous at the deep-structure level.

For every ambiguous sentence there were two unambiguous sen-

tences, one for each of the meanings of the ambiguous sentences.

Not only did the unambiguous sentences convey the same meanings

as the ambiguous sentence, but they also had the same syntactic

structures which corresponded to the meanings of the ambiguous

sentence. The purpose of this paradigm was to predict behavior

on the ambiguous sentences by performance on the unambiguous

sentences which corresponded to it. Consider the following

three sentences:

2.a. Flying planes can be dangerous.

2.b. Flying planes is dangerous.

2.c. Flying planes are dangerous.










Sentence 2.a., which is ambiguous, contains the meanings ex-

pressed in sentences 2.b. and 2.c. Sentence 2.b. contains a

nominal which can be described as an object nominal and which

can be paraphrased as 'the act of flying planes.' The entire

nominal flying planes is the subject of this sentence. Sen-

tence 2.c., on the other hand, contains a subject nominal which

can be paraphrased as 'planes which are flying.' Since flying

functions as an adjective in sentence 2.c., only the noun

planes is the subject of the sentence.

The task which the subjects were asked to perform was to

indicate which picture or pictures corresponded to the sentence

which the experimenter read. The prediction was that the stu-

dents would choose the correct picture for each of the unam-

biguous sentences, thus indicating their comprehension of

these sentences and their structures, if they were to choose

the correct pictures for the ambiguous sentence. In other

words, the student should perform correctly on sentences 2.b.

and 2.c. if he is to get 2.a. correct.


Experiment I

Method

Subjects. Forty-seven students were selected from P.K.

Yonge Laboratory School in Gainesville, Florida. There were

four groups of males and four groups of females, ranging from

8 through 11 years of age. Because of a suspected difference

in dialect, there were no black students included in the study.

All of the students were native speakers of English.










Apparatus. The test design included five pretest sentences,

used to establish that the subjects could handle the task of

pointing to one or more than one picture for each sentence that

was read, and thirty test sentences, composed of ten ambiguous

sentences and twenty unambiguous sentences. A list of these

thirty-five sentences appears in Appendix A. The twenty unam-

biguous sentences consisted of two interpretations for each

ambiguous sentence. The criteria for the ambiguous sentences

were that they be deep-structure ambiguities, that the intona-

tion pattern be the same regardless of meaning, and that they

be representable with drawings.

Of the ten ambiguous sentences, seven had as their struc-

ture nominal phrase + can be + adjective, for example, 'Visit-

ing relatives can be boring.' The unambiguous interpretations

of these seven sentences were made up of the same nominal

phrase, either the verb is or the verb are, and an adjective.

Thus the two interpretations for 'Visiting relatives can be

boring' were 'Visiting relatives is boring' and 'Visiting

relatives are boring.' These last two sentences were not

ambiguous because the verb determined whether the nominal was

to be interpreted as a subject nominal or an object nominal.

The original sentence 'Visiting relatives can be boring' is

ambiguous because there is no overt marking for number on the

verb can be.

It was also important that the adjectives in these sen-

tences be appropriate to either interpretation of the nominal.

Hence, both the act of visiting relatives and relatives who








visit may be boring. However, the sentence 'Visiting relatives

can be generous' does not offer the same duality of interpre-

tation. It is grammatical to say 'Visiting relatives are

generous,' but the counterpart 'Visiting relatives is generous'

is ungrammatical. Similarly, 'Moving houses is easy' is ac-

ceptable, whereas 'Moving houses are easy' is not. And, con-

sequently, 'Moving houses can be easy' is not ambiguous.

Two of the three remaining ambiguous sentences were com-

posed of, among other constituents, the verb stop followed by

a gerund. The ambiguity arises because there are two inter-

pretations of the subject of the gerund. These different

interpretations occur because in the deep structure there are

different subjects for the verbs which eventually become

gerunds. Consider the sentence 'The police stopped fighting

on campus.' This sentence may mean either that the police

quit fighting on campus, in which the police is the subject

of fighting, i.e., the police were doing the fighting, or

that the police ended fighting on campus, in which the subject

of fighting is some unspecified but implied agent other than

the police.

The final sentence type on the test is also one in which

a nominal construction may be interpreted in more than one way.

The test sentence is 'The shooting of the Indian was bad.'

This nominal + of + NP construction is often ambiguous because

the NP may be both the agent of the action expressed in the

nominal or it may be the object of that action. In the case

of this sentence, the Indian may be either the shooter or the

victim.







For each sentence there was a set of four pictures for

the subjects to choose from. An example of each set of pic-

tures appears in Appendix C. For the pretest sentences, in

two cases only one of the four choices was correct, and in

three cases there were two pictures which were not identical

but which were appropriate choices for the pretest sentence.

For example, for the pretest sentence 'They are riding horses,'

there were two pictures of people riding horses, but the pic-

tures differed in their details. There were also two pictures

which were not appropriate to the sentence. The purpose of

having two different pictures which corresponded to the same

sentence was to determine that the subject could perform the

task of pointing to two pictures if they both matched the sen-

tence.

For the test sentences there were also four pictures for

each sentence. For each ambiguous sentence and its two unam-

biguous counterparts, the same four pictures were used. How-

ever, the location of the pictures within each set was ran-

domized to avoid a positional bias. The four pictures con-

sisted of one picture for each meaning of the ambiguous sen-

tence and two pictures of related but different and inappro-

priate events.

All of the pictures were made into two-inch slides and

were projected onto a solid-colored wall with a Kodak Carousel

750 Slide Projector. The pictures were labeled A, B, C, or D.

The score sheet for each subject provided space for re-

cording the name, age, sex, and teacher, as well as the subject's










responses to both the pretest and test sentences. Sufficient

space was allotted for any notable comments which the subjects

may have made or for any remarks which the experimenter may

have felt necessary.


Procedure

Subjects were tested individually in a quiet room which

was dark enough to allow adequate viewing of the slides. The

subject was seated in a chair approximately six feet from the

wall on which the slides were projected. The projector was

behind and to the left of the subject. The experimenter sat

to the right of the subject and controlled the projector with

a push-button, remote-control device.

The experimenter explained to each subject that she wanted

him to tell her which picture or pictures matched the sentences

which she was going to read to him. The experimenter repeated

or rephrased the instructions when necessary. On some occasions

if the subject said he did not understand, the experimenter

said, 'Let's try one and see if you understand then.' As soon

as the first slide appeared and the subject heard the first

sentence, the experimenter asked, 'Now, which picture or

pictures go with that sentence?' Almost always, if there had

been any question in the subject's mind, he would answer, 'Oh!

Now I get it,' or something comparable.

The subject indicated which picture or pictures he felt

were appropriate by naming the letter A, B, C, or D which

labelled the pictures. At no time did the task of choosing









letters to indicate which picture or pictures the subject

felt appropriate seem too difficult.

The experimenter recorded the subjects' responses on the

score sheets, taking care to record the sequence if more than

one response were given. The experimenter also recorded any

of the subjects' comments which the experimenter felt were

valuable to this study. Some of these comments offered in-

sights into the subjects' thoughts as they participated in

this experiment. For example, in the sentence 'He wants to

prevent smoking,' several subjects asked, 'What does prevent

mean? Start or Stop?' For the sentence 'Moving houses can

be frightening,' there were comments such as 'What kind of

moving?' and 'When you're moving them or when they are moving

by themselves?' Another subject, when he heard the sentence

'Shooting stars is exciting,' commented, 'That just doesn't

seem right. Is exciting? Oh! D.' One subject who had no

problem comprehending the ambiguities found them very funny.

'A dog walking This is funny, get it?' 'That is funny.

Grownups are playing.' These and other comments provided a

valuable view of what the subjects were doing and thinking and

how they performed the tasks of this experiment.

The conditions of this experiment were informal. If a

subject did not clearly understand a sentence which was read

to him, the experimenter repeated the sentence. The task of

this experiment was based on the subject's ability to compre-

hend the structure of a sentence. It was not a test of his

ability to perceive the sentence itself. Because intonation









does not affect the reading of the sentence, repetition did

not alter any of the conditions of the experiment. Also, if

the subject had any questions and if the answers to those

questions would not alter the conditions of the experiment,

the experimenter answered the subject's questions. For ex-

ample, when one subject asked, 'What does prevent mean? Start

or Stop?' the experimenter answered, 'Stop.' However, when a

subject asked, 'What kind of moving?' in reference to the

sentence 'Moving houses can be frightening,' the experimenter

answered, 'Whatever it means to you.' An answer to the last

question on the part of the experimenter would have invalidated

the test question. There would have been no way to explain

what kind of moving without providing too much information to

the subject.

After each subject had responded to the test sentences,

the experimenter asked him to look at some of the pictures

which he had just seen and to indicate what the pictures

represented to him. This was done because there was some

question as to the interpretation of some of the pictures.

To make sure that the pictures represented to the subjects

what they represented to the experimenter, the experimenter

showed some of the slides again and asked, 'What is going on

in picture A [or any other picture]?' The experimenter did

this for usually five or six pictures per subject. Ultimately,

there seemed to be no problem with the subjects' interpretations.

The subjects generally interpreted them correctly. They often

verbalized their interpretations with the same words that they










had heard in the testing. During the test they may not have

chosen the picture of two adults playing Pin the Tail on the

Donkey (Appendix C, p. 97 ) for the sentence 'Playing grownups

can be funny.' But when they described that picture they

usually said, 'Two grownups playing Pin the Tail on the Donkey.'

Usually, in their descriptions of the subject nominals, the

ing form followed the noun: 'Two dogs walking,' 'A boy shooting

at the stars,' 'Two houses moving,' or 'A horse painting a

flower.'

The entire testing procedure took just less than ten

minutes per subject.


Results

The results of this experiment were quite different from

those which were anticipated. The expected pattern was for

the subjects to choose two pictures each for the first ten

sentences, indicating their comprehension of the ambiguities

of these sentences and to choose one picture for each of the

last twenty sentences, indicating their comprehension of these

sentences which were not ambiguous.

On the first ten sentences, those which were ambiguous,

there was no significant difference at the .05 level in per-

ception of ambiguity regardless of age as determined by the

Mann-Whitney U Test (Bruning and Kintz 1977:224). See Table

1. This perception of ambiguity was measured as the number of

times the subjects chose more than one picture to match the

ambiguous sentences. If a subject chose more than two pictures









for a sentence, and sometimes this happened, this still counted

as one instance of perception of ambiguity. This absence of a

significant difference means that the eight-year olds perceived

ambiguity as often as eleven-year olds did. This particular

finding differs considerably from the results which Frank Kessel

obtained.

Even more surprising were the results on the unambiguous

sentences. The subjects continued to choose more than one pic-

ture per sentence even for the unambiguous sentences. This

pattern of response was the same for all four age groups as

determined by the Mann-Whitney U Test at the .05 level of

significance. See Table 2. In other words, performance did

not improve with age. Regardless of age the subjects con-

sistently chose more than one picture for the unambiguous

sentences.

Frequently, the subjects chose more than one picture for

the unambiguous sentences more often than they did for the am-

biguous sentences. It appeared that the more they heard the

nominals, the more meaning they perceived for them, regardless

of the fact that the second and third times the subjects heard

the nominals, the nominals occurred in unambiguous sentences.

For example, if a subject heard 'Playing grownups can be

funny' and chose only one picture, indicating he perceived

only one meaning for the sentence, he frequently chose more

than one picture later on in the test when he heard 'Playing

grownups is funny' and 'Playing grownups are funny.' Quite

obviously, subjects who chose more than one picture for the













TABLE 1

Mean Number of Choices of Two Pictures
for the Ambiguous Sentences


Age Mean Number of Sentences


8 3.36 11
9 3.90 10
10 4.63 11
11 5.40 15


TABLE 2

Mean Number of Choices of Two Pictures
for the Unambiguous Sentences


Age Mean Number of Sentences


8 5.45 11
9 6.60 10
10 8.09 11
11 8.46 15









unambiguous sentences were responding to the ambiguity of the

nominals and not to the verb form is or are which should have

disambiguated the sentences.

Another indication that the subjects' responses were

determined solely by the meaning of the nominal, and not the

nominal in the context of the entire sentence, was the fact

that some subjects saw one meaning for an ambiguous sentence

and they continued to see that same meaning for both of the

unambiguous sentences. For these subjects, too, the verb

form is or are had no effect on their choice of picture.

Often during the testing procedure the subject would

repeat the sentence or part of it to himself. On those

occasions when the subject repeated just the nominal in an

unambiguous sentence and then selected two pictures, the

experimenter cautioned the subject to listen to the entire

sentence and then the experimenter repeated the sentence.

This, however, never had any effect. The subjects consis-

tently chose the same pictures again.

Sometimes the subjects heard an unambiguous sentence

but repeated the ambiguous version of it. The experimenter

responded with 'No; listen carefully. Playing grownups is

funny.' Although stressing the verb form violated the con-

ditions of the experiment because it should have affected the

subjects' responses, there was no effect whatsoever. No

amount of prompting changed the subjects' choices of pictures.

After the test was completed, the experimenter informally

asked those subjects who chose more than one picture for some










of the unambiguous sentences if they could distinguish between

two sentences from the test whose meaning depended on the verb

form is or are: 'Can you tell me the difference between

"Shooting stars is exciting" and "Shooting stars are exciting?"'

All of the subjects, some more consistently than others, were

able to make the distinction. They were not always correct

in their explanations, and they often had problems verbalizing

the difference, but it was definite that when the subjects

heard both sentences together, they were able to distinguish

between them.

Two of the subjects, a nine-year-old girl and a ten-year-

old boy demonstrated a thorough understanding of the principles

involved in both the ambiguous and the unambiguous sentences.

Neither selected all of the pictures correctly, but they both

improved as they progressed through the test. The female sub-

ject chose two pictures for the ambiguous sentences eight out

of ten times and for the unambiguous sentences only six out of

twenty times. The six choices of more than one picture for

the unambiguous sentences occurred early in that part of the

test. After the first seven unambiguous sentences, she chose

two pictures only once. When the experimenter asked her,

after the formal testing was completed, why she chose only

one picture for some of the unambiguous sentences, the subject

attempted to explain. She became quite confused in her ex-

planation, lacking the ability to articulate the procedure

she was using. However, she clearly understood the difference.

Her best attempt at an explanation was 'You just don't say it

that way.'









The male subject articulated more of his thoughts as

he participated in the test. For the ambiguous sentences he

chose two pictures seven times. For the unambiguous sentences,

he chose two pictures only four times. When he heard the un-

ambiguous sentences, he often repeated them slowly and thought

carefully about his answers. His comments indicated his com-

prehension of the sentences and the tasks involved: 'Shooting

stars are exciting?' He then chose the correct picture. For

the sentence 'Shooting stars is exciting,' he commented, 'That

just doesn't seem right. Is exciting? Oh! D.' And for

'Moving houses are frightening,' he responded, 'Now I get it

--houses that are moving.' This subject's indecision seemed

to imply that he had only recently acquired or was still in

the process of acquiring the ability to handle these sentences.

Although neither of these two subjects was correct on all

of the test items, each clearly demonstrated an ability to

distinguish during the test between the ambiguous and unam-

biguous sentences. It was not necessary for these subjects

to hear both unambiguous sentences of a set together in order

for them to distinguish between the sentences. These subjects

seemed well on their way to acquiring the linguistic structures

and cognitive capacities necessary for the tasks of this ex-

periment. They were the only two subjects to display this

behavior.

Because the results of this experiment were so different

from those which were hypothesized, the experimenter decided

to alter the test conditions somewhat in order to determine









the reasons for the unexpected results. Each of the changes in

the test design is considered as a separate experiment, and

each is discussed separately in the following sections.


Experiment II


Since the ambiguous sentences preceded the unambiguous

sentences in Experiment I, the ambiguous sentences may have

been causing the subjects to see more than one meaning for

the unambiguous sentences. For this reason, the order of

presentation of the test sentences was altered so that the

unambiguous sentences preceded the ambiguous sentences.


Method

Subjects. Six subjects, three male and three female,

from P.K. Yonge Laboratory School in Gainesville, Florida,

participated in this experiment. There were three groups

consisting of one male and one female. The groups were

separated by age into 8, 9, and 10 years old. All subjects

were white, native speakers of English.

Apparatus. The apparatus for this experiment were the

same as those used in Experiment I. The only change in the

apparatus was that the twenty unambiguous sentences were pre-

sented before the ten ambiguous sentences. This was done be-

cause it was felt that the subjects may have seen ambiguity in

the unambiguous sentences because they had already been exposed

to the ambiguous sentences.










Procedure

The procedure was identical to that of Experiment I.


Results

Changing the order of the sentences so that the unambiguous

sentences preceded the ambiguous sentences did not alter the

subjects' interpretations of the unambiguous sentences. Five

of the six subjects saw ambiguity in eight to eleven of the

unambiguous sentences. The sixth subject saw no ambiguity in

any of the sentences. Apparently, the order of presentation,

whether that which was used in Experiment I or that used in

Experiment II, was not relevant to the subjects' perception

of ambiguity.


Discussion

With the exception of the student who saw no ambiguity

in any of the thirty test sentences, there was no difference

by age or sex in the perception of ambiguity in both the

ambiguous and the unambiguous sentences. The results of this

experiment suggest that the order of presentation of these

sentences does not affect performance. That the subjects

perceived ambiguity in sentences that were theoretically un-

ambiguous still remained to be explained.


Experiment III


The first two experiments demonstrated four points:

1. Subjects perceived ambiguity in both the ambiguous

and the unambiguous sentences.










2. The order of presentation of test sentences may be

either ambiguous followed by unambiguous sentences or unam-

biguous followed by ambiguous sentences without any effects

in the subjects' perception of ambiguity.

3. The verb forms is and are which should have disam-

biguated the nominals did not.

4. Although the subjects perceived many of the unam-

biguous sentences as ambiguous, they were able to distinguish

between the two sentences of the pair of unambiguous sentences

when those two sentences were presented together for them to

compare. To restate this point, if the experimenter asked a

subject to explain the difference between two sentences which

differed on the surface only in the verb is or are such as

sentences 2.d. and 2.e., the subjects were almost always ca-

pable of making the necessary distinction. They did not,

however, use this information during the test situation. In-

stead, when they heard either 2.d. or 2.e., they indicated that

the sentence was ambiguous by choosing more than one picture

to match the sentence.

2.d. Moving houses is frightening.

2.e. Moving houses are frightening.

Because of these facts, it was felt that if the subjects

were exposed to sentences of the same type as those on the

test before the actual test began, and if they were given

practice in making distinctions between these sentences, this

pretest experience might encourage the students to employ this

distinction during the test.










Method

Subjects. Five students from P.K. Yonge Laboratory

School in Gainesville, Florida, participated in this experi-

ment. Of the five, four were ten years old and one was nine.

Four of the subjects, including the nine-year-old, were female,

and one was male. All of the subjects were white, native

speakers of English.

Apparatus. The apparatus for this experiment were

identical to those in Experiment I with one exception. Four

new, theoretically unambiguous sentences were added as

additional pretest items:

2.f. Bouncing balls is fun.

2.g. Bouncing balls are fun.

2.h. Flying kites is fun.

2.i. Flying kites are fun.


Procedure

The procedure in this experiment was almost identical

to that of Experiment I. The only difference was that, after

the five original pretest sentences, the experimenter pre-

sented four more pretest sentences to the subjects. The

experimenter asked each subject to listen carefully to the

two sentences which she was about to repeat. The experimenter

then asked, 'Can you tell me the difference between these two

sentences: "Bouncing balls is fun" and "Bouncing balls are

fun"?' The experimenter recorded each subject's responses

and then asked, 'Can you tell me the difference between these










two sentences: "Flying kites is fun" and "Flying kites are

fun"?' The experimenter again recorded the subject's responses

and then began the actual test. The rest of the test continued

in the same manner as in Experiment I.


Results

In general, exposure to the sentence patterns and ex-

perience in distinguishing between pairs of sentences did not

facilitate performance on the test.

Four of the five subjects chose more than one picture

for some of the unambiguous sentences. One chose two pictures

for eight of the twenty unambiguous sentences, one chose two

for nine of the twenty, one for ten of the twenty, and one

for eleven of the twenty.

Only one subject, a ten-year-old female, chose only one

picture for each of the unambiguous sentences. She chose two

pictures for five of the ten ambiguous sentences. It would

appear that she understood the task of the experiment fairly

well, except for the fact that, of the twenty unambiguous

sentences, she chose seven incorrect pictures.

Of the four who continued to see ambiguity in the unam-

biguous sentences, three demonstrated an ability to distinguish

between the two sentences in each pair that was presented in

the pretest. That ability did not, however, appear during the

test situation, since they still chose more than one picture

several times. One subject could not explain a semantic

difference between the two sentences in each pair of unambiguous










sentences in the pretest. For him, the sentences with the

verb is had the same meaning as the sentences with are, except

that he felt those with is were ungrammatical. This feeling

did not stop him during the test from choosing two pictures

for nine of the twenty unambiguous sentences.


Discussion

This test design did not help the subjects to see the

difference in the sentences with is and the sentences with are.


Experiment IV


Because none of the previous test designs consistently

elicited a distinction between the members of the pairs of

unambiguous sentences, a new design was developed. The problem

of the verb be was eliminated by changing the structure of the

sentences which had previously had can be to I like + nominal

('I like visiting relatives'), those which had is to I like

+ infinitive ('I like to visit relatives'), and those which

had are to I like + noun + that are + verb + ing ('I like

relatives that are visiting'). It was hoped that eliminating

the verb be would eliminate the subjects' problems in dis-

tinguishing between the two types of nominals.


Method

Subjects. Four students from P.K. Yonge Laboratory

School in Gainesville, Florida, were chosen to participate

in this experiment. There were two ten-year-old males and

two eleven-year-old females. All four subjects were white,

native speakers of English.










Apparatus. This test design included the five pretest

sentences which were used in Experiment I to assure that the

subjects could adequately perform the task of selecting more

than one picture if more than one picture was appropriate to

the sentence which they heard. The test sentences, which

appear in Appendix B, consisted of twenty-seven sentences,

nine of which were ambiguous and eighteen of which were unam-

biguous. Of the nine ambiguous sentences, six consisted of

I like + nominal, in which the nominal could be either a sub-

ject nominal or an object nominal. The other three ambiguous

sentences were the same three from the original test design

which were not built on the nominal + can be + adjective

structure. The unambiguous sentences consisted of the six

sentences from the original design which were not dependent on

the verb be and of twelve sentences which were interpretations

of the I like + nominal sentences. These twelve sentences

consisted of six I like + infinitive structures and six I like

+ noun + that are + verb + ing, as in the following set:

2.j. I like playing grownups.

2.k. I like to play grownups.

2.1. I like grownups that are playing.

As was true of the design for Experiment I, each unam-

biguous sentence represented one of the meanings contained in

the ambiguous sentences. Again, the purpose of this design

change was to eliminate the problems that arose with the verb

be. The remaining aspects of the apparatus--the slides,

projector, and score sheet--were the same as those in Experi-

ment I.










Procedure

This aspect was also similar to that of Experiment I.

The only difference was in the sentences that were read.


Results

On the nine ambiguous sentences, two subjects chose two

pictures seven times, one subject chose two pictures eight

times, and one chose two pictures nine times. On the eighteen

unambiguous sentences, one subject chose two pictures five

times, one seven times, one nine times, and one ten times.

This design, like the ones that preceded it, failed to

elicit a consistent distinction between subject and object

nominals. In even the most unlikely cases, for example, 'I

like to visit relatives,' two of the subjects chose two

pictures.


Discussion

No matter what the method of testing, it seemed that the

subjects could not be forced into distinguishing between when

the subject-nominal interpretation was appropriate and when

the object-nominal interpretation was appropriate. For some

reason the subjects appeared to be treating all of the nominals

as surface lexical items rather than as derived structures.


Experiment V


Because there were no age differences in either the per-

ception of ambiguity or in performance on the unambiguous

sentences, it remained unclear as to when subjects actually










begin to make the distinctions necessary to perform well on

the unambiguous sentences. Some of the results of the pre-

ceding experiments implied that the ability to interpret the

relationships among the trio of sentences made up of an am-

biguous sentence and its two unambiguous counterparts, the

ability to distinguish between the two unambiguous sentences

in the trio, and the ability to recognize that the unambiguous

sentences were in fact unambiguous were available only to

those people who have an overt interest in language. These

abilities certainly did not seem to be a part of these native

speakers' intuitions about language.

It was decided that it would be helpful to know how

college-aged adults would perform the tasks of Experiment I in

this investigation. If they had no problems with the test

sentences, then somewhere between the ages of 12 and 18 years,

there should be a point which could be labeled 'the normal

age of acquisition' of the abilities needed to handle the

elements of this test. If adults were not able to make complete

distinctions between the unambiguous sentences and were not

sure that the unambiguous sentences were unambiguous, then

these abilities most probably belong only to those people who

consciously analyze their language.

This latter possibility seems remote because it would be

quite wasteful for a language to offer distinctions for its

speakers if the speakers do not naturally utilize them. These

distinctions should not exist for the language-conscious only,










but should be an active part of any native speaker's ability

to interpret his language. On the other hand, it is possible

that this wasteful aspect is prevalent in language. Many

people may never acquire certain transformations.


Method

Subjects. Seven students from the University of Florida

were chosen haphazardly to participate in this experiment.

These students ranged from 18 to 22 years in age. Three were

males and four were females. All were white, native speakers

of English.


Apparatus. The apparatus were identical to those in

Experiment I.


Procedure

The procedure was identical to that of Experiment I. The

only change was in location. Experiment I was conducted at

P.K. Yonge Laboratory School. Experiment V was conducted in

General Purpose Building A on the main campus of the University

of Florida.


Results

On the whole, these adult subjects demonstrated a more

thorough comprehension of the elements of this test. The ten

ambiguous sentences presented more problems to these subjects

than the unambiguous sentences did. No subject chose two

pictures for all of the ambiguous sentences. The seven sub-

jects each heard ten ambiguous sentences, for a total of










seventy total exposures to the ambiguous sentences. Out of

these seventy exposures, the subjects correctly chose two

pictures twenty-nine times or 41 percent of the time.

Performance on the unambiguous sentences was much better.

Twenty unambiguous sentences presented to the seven subjects

provided one hundred forty exposures to the unambiguous sen-

tences. The subjects chose two pictures only fourteen times

out of the possible one hundred forty times, or for 10 percent

of the time. This was by far the fewest times that subjects

in any one test design chose two pictures for the unambiguous

sentences. Even though these subjects chose only one picture

for the unambiguous sentences more frequently than the subjects

in previous test situations, they chose the wrong picture

twenty-nine times or 21 percent of the time.


Discussion

In order for subjects at a particular stage in develop-

ment to have mastered a specific aspect of their language,

they should demonstrate an ability to use that part of their

language consistently. In other words, subjects should reach

an age at which it becomes useless to test them because at

that age they show no difficulty with the test items. This

does not mean that all the subjects in that age group must

get 100 percent of the items correct. There are numerous

reasons why some errors may show up. But there should be a

consistent demonstration of proficiency with the test items.

The subjects in this test have not demonstrated such a

proficiency. Perceiving only 41 percent of the ambiguities









and seeing ambiguity in unambiguous sentences 10 percent of the

time with twenty-nine errors in the choice of pictures for the

unambiguous sentences would not seem to be a demonstration of

proficiency with these test items. It is true that these sub-

jects chose two pictures only 10 percent of the time, whereas

the subjects in the previous experiments chose two pictures

from 28 percent to 39 percent of the time.

The subjects' performances during the test and their

comments after the test often indicated different things. For

example, one subject chose two pictures for only three am-

biguous sentences and chose only one picture for each of the

unambiguous sentences. Although the test demonstrated that

this subject understood the unambiguous sentences, it did not

indicate that he perceived the ambiguity in the first ten

sentences. His comments after the test, however, showed that

he understood not only the ambiguities ('with can be, it can

have two meanings') but also the design of the test ('changing

from can be to is and are'). Although this ability to describe

the test design seems quite simple, very few of the subjects,

regardless of age, were able to explain what was happening

during the test.

Another subject's performance during the test differed

from his comments after the test. This subject chose two

pictures for seven of the ten ambiguous sentences and for

five of the twenty unambiguous sentences. Yet he commented

that all of the sentences with is were ungrammatical.










Like the younger subjects, the adults were able to dis-

tinguish between sentences with is and those with are if the

two sentences were presented together for them to compare.

They, too, did not always employ this distinction when they

chose pictures.


Discussion of Experiments I Through V


An experiment was designed to determine the age at which

children develop the ability to perceive deep-structure am-

biguity as in the sentence 'Flying kites can be exciting.'

It was hypothesized that the ability to perceive both meanings

in this sentence would develop only after the child could com-

prehend both of the unambiguous sentences which represent the

meanings which are contained in this ambiguous sentence. These

two sentences are 'Flying kites is exciting' and 'Flying kites

are exciting.' The results of this experiment were completely

different from those which were anticipated.

There was no significant age difference in ability to

perceive the ambiguity of the ambiguous sentences. What the

subjects failed to comprehend was the fact that the unambiguous

sentences were unambiguous. These subjects repeatedly saw more

than one meaning for the unambiguous sentences.

In order to determine whether the subjects' behaviors were

the result of some feature of the design or if, in fact, the

subjects could not comprehend that these sentences were not

ambiguous and if not, why, four more designs were used. The

results from these four experiments indicated that with the










exception of the adults and regardless of test design the

subjects were unable to tell that the unambiguous sentences

were unambiguous, unless the pair of unambiguous sentences

was presented together for the subjects to compare. Only then

could the subjects explain the difference between the two sen-

tences and recognize that these sentences were not ambiguous.

This inability on the part of these subjects to analyze

the unambiguous sentences unless they were presented in pairs

suggests that the ability to perform such an analysis is

available only to those people who consciously analyze their

language.

Although it may seem strange that a language may offer

distinctions which its speakers do not naturally use, this

happens quite often in terms of vocabulary items which people

may never learn or use and transformations which some people

may never acquire. That many people may never be able to

distinguish between the unambiguous sentences would not hinder

their ability to communicate since most ambiguities become

disambiguated in the contexts in which they are used.

The results of these five experiments raised a large

number of questions. The most obvious question was 'why did

the subjects perform so differently from the way that the

theory had led me to predict?' This question, of course,

embodied many other questions.

Since the only difference in the surface structure in the

pairs of unambiguous sentences such as 'Flying kites is ex-

citing' and 'Flying kites are exciting' lies in the verbs is










and are, it appeared that these verbs were not meaningful to

the subjects in their interpretations of the sentences. There

was no question that the subjects heard the verbs, since the

experimenter violated the conditions of the original experi-

ment to make sure that they heard these verbs. What was un-

clear was whether it was the verb be or the presence or ab-

sence of the plural marker on the verb which was causing prob-

lems for the subjects. It seemed quite possible that it was

the verb be because this verb carries no meaning.

In order to determine which of these factors was operating,

a completely new test design was developed. This design

tested both the verb be and the plural marker in the contexts

of twelve ambiguous sentences and twelve unambiguous sentences.













CHAPTER III


EXPERIMENT VI


The subjects who participated in the first five experi-

ments demonstrated an inability to properly analyze sentences

whose structures were of the form nominal + be + adjective,

when the nominal was structurally ambiguous. The sentences

which the subjects heard were either ambiguous because the

verb form did not determine which meaning of the nominal

should be available or unambiguous because the verb form did

determine which meaning of the nominal should be available.

Sentence 3.a. is an example of the ambiguous sentence type,

and sentences 3.b. and 3.c. are examples in which the verb

form should disambiguate the nominal.

3.a. Moving houses can be dangerous.

3.b. Moving houses is dangerous.

3.c. Moving houses are dangerous.

From a descriptive standpoint, the singular form of a verb

determines that the nominal be interpreted as an object

nominal; that is, in sentence 3.b., houses is the object of

moving. The plural form of the verb determines that the

nominal be interpreted as a subject nominal; for example, in

sentence 3.c., houses is the subject of the sentence and

moving functions as an adjective modifying houses. The verb










in sentence 3.a., can be, has no inflection for number and,

consequently, provides no information to disambiguate the

nominal.

Apparently, not all native speakers, even some adults,

make these distinctions between 3.b. and 3.c. unless they

have both sentences available at the same time. Most of the

subjects in the previous experiments viewed sentences of the

form of 3.b. and 3.c. as ambiguous. It appears that the

syntactic information contained in the verb was not enough to

override the ambiguity of the nominal. It was not clear

whether the problem resided in the verb be which has no meaning

or in the presence or absence of the plural marker.

In order to determine what factors were operating for

the subjects, a new experiment was designed. Twenty-four

sentences based on the nominal + verb + adjective structure

made up the test. In this design both the verb be and the

verb look were tested in both singular and plural forms. This

was done to determine if subjects would have the same problems

if the main verb in the sentence were not some form of be.

Another variable in this design was the type of nominal.

Twelve of the nominals were ambiguous and twelve were not. All

of the nominals contained a plural noun. The subjects were

asked to select the correct verb form; that is, they were to

circle is or are in twelve sentences and looks or look in

twelve sentences. For the ambiguous nominals either form of

the verb would be correct. (See sentences 3.d. and 3.e.)









However, for the unambiguous nominals there was only one

correct verb form for each sentence. (See sentences 3.f.

through 3.i.)

3.d. Sailing boats is/are dangerous.

3.e. Sailing boats looks/look dangerous.

3.f. Making cookies is/are fun.

3.g. Making cookies looks/look fun.

3.h. Roaring lions is/are scary.

3.i. Roaring lions looks/look scary.

The nominals in sentences 3.f. and 3.g. are object nominals,

and the only grammatical verb form in each sentence is the

singular form. The nominals in sentences 3.h. and 3.i., how-

ever, are subject nominals and are grammatical with only the

plural form of the verb.

Because the subjects in the previous experiments had

viewed sentences such as 3.d. as ambiguous, it was suspected

that the subjects in this experiment might do the same. It

was also expected that some subjects might choose the plural

verb form for all of the nominals because the nominal phrases

end in s and the plural noun is next to the verb. This type

of behavior constitutes a strategy which may not always pro-

duce the correct result. For example, in sentence 3.f. some

speakers may choose are because the noun cookies, which is

plural, is next to the verb. Although the word cookies is

not the subject of the sentence, it was felt that some speakers

might behave as if it were. Such a strategy would generate

the ungrammatical sentences 3.j. and 3.k.










*3.j. Making cookies are fun.

*3.k. Making cookies look fun.

This strategy applied to subject nominals also generates the

plural verb form, but in this case, it is the correct form.

If this strategy is actually being utilized, there should be

significantly more errors with object nominals than with sub-

ject nominals.

The subjects' behavior on this test should indicate the

importance of the verb form in interpreting the nominal. If

there were not significantly more errors with object nominals

than with subject nominals, it might mean that the verb form

was irrelevant to the interpretation of nominals. This would

follow if the syntactic information contained in the verb were

not enough to override the ambiguity of the nominal.

There were two other questions which this design attempted

to answer:

1. Is there a developmental point at which the verb be-

comes relevant to the interpretation of the nominal?

2. Is this linguistic behavior in any way a function of

education?

It seems that the ability to distinguish between 'Flying

kites is fun' and 'Flying kites are fun' should not be related

to how well a person has learned his English grammar lessons.

Since the two sentences represent differences in meaning, they

should be different to all native speakers of English, who

presumably cut up the semantic spectrum along the same lines.

There is some indication, however, that these sentences have










the same meaning for some speakers, and consequently, they do

not share the same divisions of the semantic spectrum with

those speakers for whom these two sentences have different

meanings. It may happen that the only explanation for this

linguistic behavior is that, unless the subject is overtly

and consciously aware of the rules of his grammar, he does

not attend to all the grammatical technicalities of a sentence.

These subjects rely, quite probably, on context. Contextual

factors ordinarily eliminate the need to analyze a sentence

closely enough to determine whether a speaker is talking

about the act of flying kites or about kites which are flying.

It was in an attempt to sort out some of these factors

that the following experiment was run.

Method

Subjects. One hundred eighty-three subjects participated

in this experiment. One hundred thirty of these subjects were

students between the ages of seven and twelve years old from

P.K. Yonge Laboratory School in Gainesville, Florida. The

other fifty-three subjects were students at the University of

Florida between the ages of eighteen and twenty-nine. In all

there were eighty-nine females and ninety-four males. All sub-

jects were native speakers of English. In this experiment

there were no restrictions on race.

Apparatus. The apparatus consisted of one sheet of paper

for each subject with places at the top for name, age, and sex

and with twenty-four sentences, each containing the singular









and the plural forms of the verb be in the present tense or

the verb look in the present tense. All of the sentences had

a nominal + verb + adjective format. In twelve of the sen-

tences the nominal was ambiguous; that is, it could be either

a subject nominal or an object nominal (for example, 'flying

kites'). For these twelve sentences, both the singular and

the plural forms of the verb were grammatical. In the other

twelve sentences the nominals were not ambiguous; six nominals

were subject nominals and six were object nominals. The sub-

ject nominals were grammatical with only the plural verb, and

the object nominals were grammatical with only the singular

verb. Each nominal in the test was paired with the verb be

in one sentence and the verb look in another sentence. The

order of the sentences on the test was random. A copy of

this test is in Appendix D.

Procedure

This test was administered in the classrooms at P.K.

Yonge and at the University of Florida by the classroom in-

structors. Each instructor passed out the test forms and

directed the students to read each sentence carefully and to

circle the correct form of the verb. No other instructions

were given. However, for one group, an adjustment had to be

made. The youngest group, the seven-year olds, was incapable

of reading the test, so their teacher read it out loud to

them. Because intonation pattern does not affect the meaning

of these sentences, no problems arose from the sentences being

read aloud.









Two forms of this test were administered. In one form

the order of the twenty-four sentences was the reverse of the

order for the second form. One half of the subjects received

form one and the other half received form two.

The data were analyzed using the SAS General Linear Model

Procedure computer program for analysis of variance. In the

ambiguous sentences subjects could not make an error in their

choice of verb form. However, because it was thought that

subjects might employ a strategy of selecting the plural form

of a verb because the noun which precedes the verb is always

plural, it was important to know whether the subjects chose

the singular or the plural form of the verb in the ambiguous

sentences. Therefore, in order to distinguish the responses

for the unambiguous sentences from those for the ambiguous

sentences, the verbs were divided into six categories: two

singular--is and looks, two plural--are and look, and two

categories labelled be and 1k for the ambiguous sentences.

The subjects' responses were recorded in the following manner:

for the unambiguous sentences, a correct response was coded

as 0, and an incorrect response was coded as 1. Because there

was no way to make an incorrect choice of verb in the ambiguous

sentences, selection of the singular verb form was coded as 0

and of the plural verb form was coded as 1.

The data were also analyzed from the perspective of the

nominals. There were three categories of nominals. For the

unambiguous sentences the categories were either Subject or

Object nominals. For the ambiguous sentences, the nominal









could be interpreted as either subject or object, and, there-

fore, the category for the nominals in the ambiguous sentences

was labelled Subj-Obj. The numbers in the first two categories

were the number of times the subjects chose the wrong verb form

for a particular nominal type. The numbers in the category

Subj-Obj were the number of times subjects chose a plural verb

form for the ambiguous sentences. The responses for nominals

also represent a collapsing of the verbs which were appropriate

for the particular nominal type. For example, the mean for

nine-year-old males with respect to subject nominals represents

a collapsing of the scores for nine-year-old males on the verbs

are and look because these two verb forms are the correct re-

sponses for subject nominals.

One final point, all of the subjects older than twelve

were combined into one group. The subjects actually were be-

tween the ages of eighteen and twenty-nine, but they were all

considered in one age group which was labelled 21-year olds.

Results

Verbs in unambiguous sentences. For those sentences

which were not ambiguous, there was a three-way interaction

of sex, age, and verb which was significant at the .01 level.

The two-way interaction of sex and verb was not significant at

the .01 level. The age by verb interaction and the sex by

age interactions were significant, the former at an alpha level

of .0001 and the latter at an alpha level of .0027. Although

the main effect of sex was not significant, the main effects

of age and of verb were significant at the .0001 level.









Figures 1 through 4 indicate the percent of incorrect responses

for male and female subjects at each age interval for the four

verb forms. Figure 1 indicates the number of times subjects

chose the verb are when the correct response was is. Figure

2 indicates the number of incorrect responses for are, Figure

3 for looks, and Figure 4 for look. If the four figures are

imposed on one graph, the three-way interaction becomes evi-

dent. These scores are also listed in Table 3.

Is. When the correct response was is, the seven-year-old

male and female subjects' performances of 47 and 42 percent

respectively were not significantly different. The eight-year-

old subjects were not significantly different either from each

other or from the seven-year olds. The nine-year-old males

continued to perform in the same manner as the seven- and

eight-year olds. The nine-year-old females, however, improved

significantly, choosing the verb form are only 28 percent of

the time when they should have chosen is. At the age of ten,

female subjects performed just as the nine-year-old females.

The males, however, did worse at this age than at any other

age, choosing are 60 percent of the time when they should have

chosen is. The responsesof the eleven-year olds were almost

the reverse of those for the ten-year olds. The male subjects'

scores improved to 24 percent, while the females' scores

worsened by 28 percentage points to 57 percent. For the

twelve-year olds, there was another reversal. The males'

scores rose to 43 percent incorrect, while the females improved

by 40 percent to 17 percent incorrect. Finally, the scores









for male and female adults were nearly identical at 11 percent

and 12 percent, respectively.

Are. The subjects' behavior when the correct response

was are remained more consistent. At the ages of 7, 9, 10,

and 11, females did slightly, but not significantly, better

than males. At the ages of 8 and 21, males did slightly better.

And at the age of 12, both males and females had an identical

score of 0 percent incorrect responses.

Looks. At the age of 7, male subjects chose the verb

form look 13 percent of the times when they should have chosen

looks, whereas the females did this 18 percent of the time.

At the age of 8, both males and females did worse than the 7

year olds. The females made errors 26 percent of the time,

while the males were incorrect 44 percent of the time. At the

age of 9, the males improved to 33 percent and the females

improved to 4 percent. At the age of 10, both males and

females made errors 17 percent of the time. At 11, males

improved slightly to 12 percent and females remained almost

the same at 18 percent. At 12, the males had slightly more

errors--14 percent, and females made slightly fewer errors--8

percent. The adult males again improved slightly, this time

to 9 percent, and the females made errors 15 percent of the

time. From the age of ten to adult, none of the scores was

significantly different. Although the scores for male and

female subjects alternated in terms of which sex had fewer

errors at each of these ages, the fact that there was no
















TABLE 3


of Incorrect
by Male


Responses on the Four
and Female Subjects


Verb Forms


Age Sex Is Are Looks Look


7 M 47 13 13 53
7 F 42 6 18 30
8 M 49 10 44 33
8 F 46 13 26 49
9 M 45 9 33 55
9 F 28 5 4 48
10 M 60 17 17 33
10 F 29 13 17 28
11 M 24 15 12 18
11 F 57 9 18 27
12 M 43 0 14 0
12 F 17 0 8 25
21 M 11 1 9 4
21 F 12 1 15 3

Note. All scores are rounded off to the nearest
percentage point.


Percent
















60-

55- .

50-

45- ..* .' **

40- *,

o 35-

H30- .......

Z25-

20-

15- '*.

10-

5-

0 -, -----
7 8 9 10 11 12 21
AGE

a-: Male
******* Female


Figure 1. Percent of incorrect responses for the verb
form Is by male and female subjects.
























U40



H30-

Z25-

S20-

15

10- .. -

5- *** '*.


7 8 9 10 11 12 21
AGE

S-, Male
.... Female



Figure 2. Percent of incorrect responses for the verb
form Are by male and female subjects.































. .e.
*" "
*e
*

*


45-

S40-

S35-
0
U
Z 30-

H25-
z

20-

15-

10-

5-

0 1


*- Male
**.... Female


Figure 3.


Percent of incorrect responses for the verb
form Looks by male and female subjects.


I I I 1 I 1
7 8 9 10 11 12 21
AGE
















60 -

55-

50-

45- ."

D40-

S35- '.

H30 -

U *
25- "" ***.

215 \'.
20

15-

10-

5

00
7 8 9 10 11 12 21
AGE

--- Male
**.... Female



Figure 4. Percent of incorrect responses for the verb
form Look by male and female subjects.









significant difference in these scores indicates that there

was no genuine improvement after the age of 10.

Look. At the age of 7, male subjects chose looks 53

percent of the times that they should have chosen look. Fe-

male subjects chose looks incorrectly 30 percent of the time.

At eight, male subjects chose looks incorrectly 33 percent,

while females made errors 49 percent of the time. Nine-year-

old male and female subjects made errors 55 and 48 percent of

the time, respectively. Both male and female subjects improved

significantly by the age of ten to 33 and 28 percent, respec-

tively. At 11, males improved to 18 percent while females

stayed at 27 percent. At 12, the males again improved; this

time they made no errors. The females improved slightly to

25 percent. As adults, the male subjects made errors only

4 percent of the time and females improved to 3 percent.

Nominals in unambiguous sentences. This category is

simply a different perspective on the same data. The scores

are the combined scores for both the verbs which were gram-

matical for a particular nominal type. For example, in the

sentence 'Growling lions is/are--looks/look scary,' both are

and look are grammatical because this sentence contains a

subject nominal. These scores, then, indicate the number of

errors in choice of verb that males and females at each age

interval made for a particular type of nominal. The purpose

of looking at these data in this manner is to determine which

type of nominal presented more difficulty to the subjects.










The result of this analysis was that there was a signifi-

cant three-way interaction of sex, age, and nominal at the .01

level of significance. The two-way interactions of sex by

nominal and of age by nominal were not significant at the .01

level. The sex by age interaction was significant at the

level of .0047. The main effect of sex was not significant,

but the main effects of age and of nominal were significant

at the level of .0001. These scores are listed in Table 4

and the interaction is evident in Figure 5.

At the age of 7, male and female subjects made errors

with object nominals 30 percent of the time. For the subject

nominals, males made errors 33 percent and females 18 percent

of the time. At eight, male subjects improved on subject

nominals to 22 percent but had 46 percent incorrect with ob-

ject nominals. Females made more errors on both subject and

object nominals, 31 percent and 40 percent, respectively.

At nine, males improved with object nominals to 39 per-

cent but with subject nominals they were incorrect 32 percent

of the time. The females improved on subject nominals to 26

percent incorrect and on object nominals to 17 percent in-

correct.- At 10, the males stayed the same on object nominals

but improved with subject nominals to 25 percent incorrect.

Females improved with subject nominals to 20 percent but had

23 percent incorrect on object nominals. At the age of 11,

male subjects improved somewhat to 17 percent on subject

nominals and improved significantly to 18 percent on object



















TABLE 4

Percent of Incorrect Responses on Subject and Object
Nominals by Male and Female Subjects


Age Sex Subject Nominal Object Nominal


7 M 33 30
7 F 18 30
8 M 22 46
8 F 31 40
9 M 32 39
9 F 26 17
10 M 25 39
10 F 20 23
11 M 17 18
11 F 18 38
12 M 0 29
12 F 13 13
21 M 2 10
21 F 2 14

Note. All scores are rounded off to the nearest
percentage point.






61












50-

45- A.
40- /

E35 /

I30- .30
0
u25- \

g20- .* *.. \

'15 -
a0- \ ".

5-

0
7 8 9 10 11 12 21
AGE

Subject Nominals, Males
.****** Object Nominals, Males
--- Subject Nominals, Females
Object Nominals, Females



Figure 5. Percent of incorrect responses on subject and
object nominals by male and female subjects.







nominals. Female subjects improved just slightly to 18 percent

with subject nominals but made significantly more errors, 38

percent, with object nominals.

For the 12-year olds, there was a 29-point divergence

between the scores for the male subjects, as they had 29 per-

cent incorrect with object nominals and no errors with subject

nominals. The female subjects made errors 13 percent of the

time for both subject and object nominals. Adults were more

consistent by sex. The males had 10 percent incorrect for

the object nominals while females had 14 percent incorrect

for the object nominals, and both sexes had 2 percent incor-

rect for the subject nominals.

Verbs in ambiguous sentences. The scores in this cate-

gory indicate the percentage of times that the subjects chose

a plural verb form in each ambiguous sentence. The results

were that the three-way interaction of sex by age by verb and

the two-way interaction of sex by verb were not significant

at the .01 level of significance. The two-way interactions

of verb by age and of sex by age were significant to the

level of .0001. The main effect of sex was not significant

at the .01 level, whereas the main effects of verb and of age

were significant to the .0001 level. Table 5 contains a list

of the scores for the verb-by-age interaction. Figure 6 in-

dicates the percentage of plural verb forms that the subjects

chose for each main verb at each age interval for those sen-

tences which were ambiguous.


















TABLE 5

Percent of Choices of Are and Look
in the Ambiguous Sentences


Age Are Look


7 38.0 75.0
8 35.0 62.0
9 54.5 77.0
10 57.0 79.0
11 44.5 77.5
12 71.5 63.5
21 76.5 75.0

Note. All scores are rounded off to the nearest
one-half percentage point.






64









30-
...*** .**** ...
O 75- *. ..
0
70

65-

S60-

0 55-

W 50-
H
O 45-
U
40-
O
E 35-
z
U 30-

S25-

20 a i |
7 8 9 10 11 12 21
AGE

.-. Are
******* Look



Figure 6. Percent of choices of Are and Look in
the ambiguous sentences.









There is a pattern from the age of 7 through the age of

11 for the subjects to choose the plural form at least 23 per-

cent more often for the main verb look than for the main verb

be. The differences were significant at the .01 level at the

ages of 7, 8, 10, and 11. At the ages of 12 and 21, subjects

chose slightly more plural forms for be than for look. The

differences for these two ages were not significant. Overall,

as the age of the subjects increased, the choices of plural

verb forms also increased. The choices of plural verb form

for the verb look in the ambiguous sentences were between 62

percent and 79 percent for all ages. However, for the verb

be the percentage of plural responses ranged from 35 percent

for the eight-year olds to 76.5 percent for the adults.

The scores for the age-by-sex interaction are listed in

Table 6, and Figure 7 illustrates this interaction. At the

ages of 7, 8, 11, 12, and 21, male subjects chose plural verb

forms more often than female subjects did. The females chose

more plurals at the ages of 9 and 10. Only the differences

at the ages of 10 and 11 were significantly different at the

.01 level. From the ages of 7 to 8 there was a decline in

plural choices for both sexes. From 10 to 11, there was a

decline in the plural choices for females. From 11 to 12,

there was a slight decline among the male subjects. In all

other instances, the number of choices of plural verb forms

increased.

Nominals in ambiguous sentences. Again, to look at the

nominals is simply to look at the same data from a different


















TABLE 6

Percent of Choices of Plural Verb Forms in the
Ambiguous Sentences by Male and Female Subjects


Age Male Female


7 65.0 48.0
8 49.0 47.0
9 59.5 72.5
10 61.0 75.0
11 73.5 48.0
12 68.0 66.5
21 76.0 75.0

Note. All scores are rounded off to the nearest
one-half percentage point.

















80-

75 -

70-

65 -

60-

55 -

50 -

45 -

40 -

35 -

30 -

25 -

20


I I i I I I I
7 8 9 10 11 12 21
AGE


p.- Male
**.*** Female


Figure 7.


Percent of choices of plural verb forms in the
ambiguous sentences by male and female subjects.


*6*










perspective. In this case, to look at the number of times

that the subjects chose a plural verb form is to determine

how often they interpreted the ambiguous nominal as a subject

nominal. The result was a two-way interaction of sex and age

which is significant at the .01 level. The main effect of

sex was not significant at the .01 level. However, the main

effect of age was significant at the .0001 level of signifi-

cance. The scores for the nominals in the ambiguous sentences

are the same as the scores for the age-by-sex interaction for

verbs in ambiguous sentences. Therefore, Table 6 and Figure

7 are applicable here and will not be repeated.














CHAPTER IV


DISCUSSION


Because of the significant three-way interactions, it

is impossible to draw any clear conclusions about the data.

There are, however, some trends which can be discussed.

Verbs in unambiguous sentences. When the correct re-

sponse was are, the subjects had the fewest problems. The

highest percentage of errors with are was 17 percent for the

ten-year-old males. Performance with this verb form was also

the most consistent: There was considerably less fluctuation

in the scores for this verb form than for the others.

For all four verb forms, the number of errors for the

twelve-year olds and adults was smaller than the number of

errors for the seven-year olds. The greatest amount of im-

provement occurred with the verb forms look and is. The

least amount of improvement occurred with looks.

Between the ages of seven and eleven, the subjects'

performance on the two plural forms look and are never over-

lapped as there were significantly more errors with look at

the ages of seven, eight, and nine, and for the ten-year-old

males. With the exception of the twelve-year-old female sub-

jects' performance with look, all the twelve-year olds and

adults had almost identical scores on look and are, and those










scores were equal to 0 percent for the twelve-year olds and

very close to 0 percent for the adults. Consequently, the

twelve-year-old and adult subjects had fewer problems when

the correct answer was a plural verb form.

Nominals in unambiguous sentences. This perspective on

the data also indicates that there can be no automatic con-

clusions. The seven-year-old subjects performed better than

the eight-year olds in all cases except for the males with

subject nominals. After the age of eight, performance on the

object nominals was highly inconsistent for both males and

females. Females began to improve after the age of eight with

subject nominals, and they continued to do so all the way to

adults. Males did worse as nine-year olds with subject

nominals, but after that they steadily improved. At the age

of twelve they had 0 percent incorrect with subject nominals,

and as adults, their score of 2 percent incorrect was not

significantly different from 0 percent. The adults' per-

formances on object nominals of 10 percent incorrect for males

and 14 percent incorrect for females, although higher than

that of the subject nominals, were not significantly different.

All of the subjects seemed to acquire the ability to handle

subject nominals earlier and more completely than they did

object nominals.

Verbs and nominals in ambiguous sentences. The scores

in this category are the number of times that subjects chose

a plural verb form (are or look) in the ambiguous sentences,

or, in other words, how many times they interpreted the nominals









in the ambiguous sentences as subject nominals. Between the

ages of seven and eleven the subjects interpreted the nominals

in the ambiguous sentences as subject nominals 23 percent to

37 percent more often for those sentences with look than for

those with be. At the age of twelve and as adults, subjects

interpreted the nominals with be as subject nominals more

often than those with look. Thus the interaction of age and

verb was significant. As adults the subjects' performances

with both verbs were nearly identical. The scores for look

were high for all ages and finished at 75 percent. The scores

for be were as low as 38 percent and 35 percent for the seven-

and eight-year olds, respectively, and finished at 76.5 per-

cent for the adults. Consequently, the subjects showed a

tendency to choose the plural form more often as they got

older.

Having considered the statistical results of this test,

we should attempt to answer those questions which were posed

at the outset of this experiment.

Since the subjects in the first five experiments perceived

so many sentences as ambiguous, would the subjects in this

experiment perceive ambiguity in this format? Not only did

the subjects not perceive ambiguity in the unambiguous sen-

tences, they did not indicate that they perceived the ambiguity

in those sentences that were ambiguous. One subject, a twenty-

two-year-old female selected one verb for each sentence but

noted (incorrectly) at the bottom of the test form that all

of the sentences were ambiguous, and, therefore, all of the









verb forms were appropriate. All other subjects selected

only one verb form for each sentence. It is, however, quite

possible that the instructions--'Circle the correct verb form

in each sentence'--influenced the subjects' performance.

The subjects in the first five experiments did not

seem to use the syntactic information available in the verbs

in the test sentences. Because the verb forms in these

sentences were forms of the verb be, a verb which is

semantically empty, it was felt that some of the problems

which the subjects encountered might be related to the

nature of the verb be. For that reason, the verb look was

included in this experiment. If the subjects had problems

with be but not with look, then there would be evidence that

the semantically empty verb be was responsible for the prob-

lems of the subjects in the first series of experiments. If

the subjects had as many or more problems with look as with

be, then their problems must reside with the syntactic in-

formation carried by the verb and not with the semantics.

The subjects in this experiment had almost identical

totals of errors with be and look. If the scores for the

verb forms is and are are collapsed, and if the scores for

looks and look are collapsed, and if the sexes are collapsed

for both main verbs, the result is one score each for the

main verbs be and look at each age interval. These scores

are listed in Table 7 and graphed in Figure 8. It was

pointed out earlier that the three-way interaction of age,

sex, and verb in the unambiguous sentences was significant.






73







TABLE 7

Percent of Incorrect Responses for the
Main Verbs Be and Look


Bea


Lookb


7 27.0 28.5
8 29.5 37.5
9 22.0 35.0
10 29.5 23.5
11 26.5 18.5
12 14.5 12.0
21 6.0 7.5

Note. All scores are rounded off to the nearest one-
half percentage point.
aThe scores for Be represent the collapsing of the
scores for the verb forms is and are for both males and
females.
bThe scores for Look are the collapsed scores for
looks and look for both males and females.


Age




















.* .
*.
*
**
e


40-





35-





30-





0 25-


0
U
z
H20-


U


S15-





10-





5





0


I I
9 10
AGE


-., Be
*******.. Look


Figure 8.


Percent of incorrect responses for the main
verbs Be and Look.


0
*m


12 21










Because of this significance, collapsing verbs and sexes is

not legitimate statistical procedure. However, having one

score for the main verbs makes comparison of those verbs

easier. So, keeping in mind that this is a violation of

statistical procedure and that, as a result, it obscures

a large amount of information, this information will be

considered in collapsed form.

Seven-year olds had nearly equal trouble with be and

look, with an average of 27 percent and 28.5 percent in-

correct, respectively. Eight-year-old subjects had more

errors with both verbs: slightly more with be at 29.5

percent and somewhat more with look at 37.5 percent. The

greatest discrepancy occurred at the age of nine. These

subjects improved to 22 percent with be and to 35 percent

with look, for a difference of 13 percentage points between

the two. At the age of ten, subjects had more problems with

be, averaging 29.5 percent incorrect and improved considerably

with look to an average of 23.5 percent. After the age of

ten, subjects improved with both verbs at each age interval.

The seven-, eight-, and nine-year olds and adults had more

problems with look while the ten-, eleven-, and twelve-year

olds had more problems with be. It appears that the sub-

jects began to resolve their problems earlier with look than

with be, since their scores improved from the age of eight

onward, whereas they did not improve consistently with be

until after the age of ten.










Overall, the subjects' performances with be and look

were quite similar. There seems to be no evidence that

the semantically empty nature of be was responsible for

the problems which the subjects had in this syntactic con-

text.

The third area under investigation was how the subjects

would handle the singular and plural verb forms. It was

suggested that if the subjects had problems in their choice

of verb form, they would choose the plural verb form more

often because in every sentence, regardless of its phrase

structure, a plural noun occurred immediately before the

verb.

There are two ways to determine how the subjects handled

singular and plural markers. The first way was to look at

the subjects' performance with nominals in the unambiguous

sentences. Figure 9 represents the information presented

earlier as Figure 5, with the exception that the variable

sex has been collapsed. Again, the collapsing is a viola-

tion of statistical procedure because of a significant three-

way interaction of sex, age, and nominal, but it provides

a clearer comparison of the nominals. Figure 9 and Table 8

indicate that for every age except nine the subjects had

more problems with object nominals than with subject nominals.

This means that the subjects chose plural verb forms when

they should have chosen singular forms more often than they

chose singular when they should have chosen plural. Eight-

year olds made the most errors in choice of plural form.






77









TABLE 8

Percent of Incorrect Responses on Subject and Object Nominals


Age Subject Nominals Object Nominals


7 25.5 30
8 26.5 41
9 29.0 28
10 22.5 31
11 17.5 28
12 6.0 21
21 2.0 12

Note. All scores are rounded off to the nearest one-
half percentage point. The variable sex has been collapsed.




















50-

45-

E 40 .*'.

35- .'
O .*.
U 30 .****-..
z
H 25-

S20-

M 15-

10-

5-

0 II II
7 8 9 10 11 12 21
AGE

-__-* Subject Nominals
*....** Object Nominals


Figure 9. Percent of incorrect responses on subject
and object nominals.










Adults made the fewest errors with both singular and plural

forms.

The second perspective on singular and plural markers

is in the subjects' performance with the ambiguous sentences.

Figure 10 and Table 9 indicate the number of times that the

subjects chose are and look in the ambiguous sentences. Sex

and verb are collapsed in this figure, and consequently, a

lot of information is obscured. However, for the purposes

of this point, this information is sufficient. Because this

figure indicates the percentage of plural verb forms which

the subjects chose at each age interval, the percentage of

singular forms chosen can be determined by subtracting the

percentage of plural choices at a particular age from 100

percent. Therefore, nine-year-old subjects chose a plural

verb form 66 percent of the time for the ambiguous sentences,

and they chose a singular form 34 percent of the time.

Figure 10 clearly indicates a tendency to choose the plural

verb form more often than the singular verb form. Only at

the age of eight did the subjects choose a singular form

more often than a plural form. There was also a tendency,

although not as consistent, for the subjects to choose plural

forms more often as they get older. Adults chose a plural

verb form 76 percent of the time for the ambiguous sentences.

Both of these perspectives indicate a tendency on the

part of the subjects to choose a plural form in the context

of the test sentences. There are at least two explanations

for this linguistic behavior. In some instances the subjects
















TABLE 9

Percent of Choices of Plural Verb Forms
in the Ambiguous Sentences


Age Plural Verb Forms


7 56.5
8 48.0
9 66.0
10 68.0
11 60.5
12 67.0
21 75.5

Note. All scores are rounded off to the nearest one-
half percentage point. Both sex and verb have been collapsed.



































60 -

55 -

50 -

45 -


10 11
AGE


12 i1


0 Plural Verb Forms


Figure 10. Percent of choices of plural verb forms
in the ambiguous sentences.


_ _1









may be employing a strategy of choosing a plural verb form

to agree with the plural noun that precedes the verb, rather

than analyzing the structure of the nominal. The second

possible explanation is that the subjects chose a plural

verb form because they interpreted the nominal as a subject

nominal. The structure of a subject nominal is 'simpler'

than that of an object nominal. The problem of linguistic

simplicity is still unsolved; however, in this case there

are several reasons to believe that the meaning of a subject

nominal is more readily apparent than that of an object

nominal.

First, the interpretation of the subject nominal does

not require any information which is not available on the

surface. Visiting relatives in the sense of 'relatives

that are visiting' has lost no content in the derivation

since that and are are not content words. Visiting rela-

tives in the sense of 'someone is visiting relatives' loses

the information carried by the subject of visiting. Although

that subject may be unspecified, it is still implied by the

structure. Also, the subject of visiting may be specified

by the context of the sentence or in the manner of 'Visiting

relatives is boring to Jane' in which Jane appears overtly

in the sentence as well as being the deleted subject of

visiting. Consequently, the listener must supply informa-

tion in order to interpret an object nominal, but all of the

information is available in a subject nominal.









Secondly, although the subject nominal is derived

from a deep-structure sentence, it resembles other adjective

+ noun combinations. The test sentences with subject

nominals as their subjects have the more common composition

of adjective + noun + verb + adjective, whereas the sentences

which have object nominals as their subjects have the com-

position of Iverb + objects + verb + adjective. Thus, the
subject

listener must analyze the structure of an object nominal in

order to understand it, whereas it is possible to interpret

a subject nominal on the basis of its lexical content.

If, in fact, the interpretation of a nominal as a

subject nominal is more readily available to the subjects,

this would explain why subjects interpreted the nominals

as subject nominals more frequently than as object nominals,

and, therefore, why they chose plural verb forms more often.

Figures 9 and 10 seem to have some contradictory indi-

cations. As the subjects get older they choose a plural

verb form/interpret a nominal as a subject nominal more

often if the sentence is ambiguous. However, as subjects

get older they make fewer errors of choosing plural forms/

interpret object nominals as subject nominals less often

in the unambiguous sentences.

It may be that as they get older the subjects rely

heavily on the strategy in the ambiguous sentences, or

possibly, when there is no reason not to do so they inter-

pret the nominal as a subject nominal. And for the










unambiguous sentences the subjects' performances may improve

because, as they become older, the subjects acquire a better

understanding of the structure of the object nominal, as well

as its relationship with the verb. It may, in fact, be the

case that the subjects actually acquire Pro Deletion Trans-

formation--one transformation which is necessary for the

derivation of an object nominal--during the age span that

was tested in the experiment.

The numerous errors in subject/verb agreement make it

evident that, at least through the age of twelve, the sub-

jects do not fully understand the relationship between the

nominal type and the number of the verb. This, to some

degree, explains why many of the subjects in the first series

of experiments failed to attend to the verb is or are in

determining the meaning of the nominals in the test sentences

and, instead, perceived the sentences as ambiguous. The

only group of subjects who consistently demonstrated an

understanding of the relationship between the nominal and

the number of the verb was the adults. With the verb form

are, subjects never had many problems. And with looks, the

subjects began at about the age of ten to have fewer problems.

But for is and look, the age of understanding was somewhere

between twelve years and adults.

One final question which was considered was the role of

education in this linguistic behavior. As was mentioned

earlier, the difference between 'Moving houses is dangerous'

and 'Moving houses are dangerous' should be available to all










native speakers because it represents a difference in meaning.

However, not all subjects demonstrated a comprehension of

this difference. Could it be that this distinction is avail-

able only to those speakers who have learned the rules of

subject/verb agreement and for people such as linguists who

are highly conscious of the nuances of their language? Al-

though education was not a variable that was controlled in

these experiments, it is safe to say that education is not

a determining factor. Numerous studies have shown that

attempts to impose a rule onto a speaker's grammar before the

speaker reaches the normal stage of acquisition for that

rule confuses the speaker rather than speeding up the

acquisition process (McNeill 1966 and Braine 1971). It

is also true that the eight-year-old and older subjects in

the first five experiments were able to distinguish between

these two sentences if the sentences were presented together

for the subjects to compare. Apparently they have internalized

the information which is necessary to tell the difference

between the two sentence types if both are present. Possibly

they compare some features of the two sentences. But if

only one sentence is present so that there is nothing for

the subjects to compare that sentence with, they seem to

rely only on the lexical information in the surface structure.

This tactic leads them to comprehend two meanings in either

sentence. That is, they see the ambiguity which exists in

the nominal in sentences 4.a. and 4.b., but they do not rely










on the syntactic information of the verb to enforce a choice

between the two meanings. For this reason many of the sub-

jects in the first five experiments treated the unambiguous

4.a. Moving houses is dangerous.

4.b. Moving houses are dangerous.

test sentences as if they were ambiguous.

At some point in the acquisition process, speakers may

acquire an ability to compare sentence 4.a. with sentence

4.b. internally. That is, they may hear sentence 4.a. in

isolation and may be able to analyze it by generating sentence

4.b. and comparing the two. Possibly the subjects in these

experiments had not reached this point. They were able to

compare the two sentence types if both were presented by the

experimenter. But they were not able to generate the second

sentence internally on their own.

The problems which these subjects manifested under the

test conditions imply that the subjects would have difficulties

in normal communication. According to the results of these

experiments, on hearing the sentence 'Moving houses is

dangerous,' the subjects would comprehend two different

meanings and would be forced to guess which meaning the

speaker had intended. However, this would not, in fact, be

a problem. The context of a conversation would provide enough

information so that no choice would have to be made.

The conditions which occurred in the test situation and

which occur in the context of a conversation may differ in

that in a conversation the subjects do not need to compare










the potentially ambiguous sentence with any other sentence

because the meaning has been specified by the context. In

the test conditions if the experimenter offered no sentence

for comparison and if the subject had not acquired the ability

to generate the sentence for comparison, then the subject had

no method with which to disambiguate the nominal. A subject

at this stage would then perceive sentence 4.a. and sentence

4.b. as ambiguous.

There are two suggestions for any further investigation

or follow-up studies.

1. In experiment six the verb forms are and looks

always occurred in the second position for the subjects to

choose from (see Appendix D). It was also the case that the

subjects chose are and looks more often than they chose is

and look. It is possible that the subjects responded in this

manner because of a recency effect of selecting the verb form

which they encountered last. For this reason it is suggested

that, in any future study of this type, the order of the verb

forms not be the same throughout the test.

2. One of the test sentences in experiment six was

'Making cookies is/are looks/look fun.' Although the correct

verb forms for this sentence are is and looks, it is possible

that 'Making cookies look fun' is a grammatical phrase, as

in the sentence 'Mother always makes making cookies look fun.'

Although 'Making cookies look fun' is not grammatical as a

sentence, it and other phrases which may be interpreted as






88



grammatical parts of sentences could present some problems

in similar test designs.

This study indicates that a study of ambiguity or other

studies based in the theory of transformations must consider

not just a set of transformations but also the specific

lexical items--for example, the verb forms--which are in-

cluded in the study.














CHAPTER V

CONCLUSION


The first experiment in this study was based firmly in

the theory of Transformational Grammar, so much so that it

seemed almost uninteresting to attempt to prove the obvious.

It seemed unquestionable that sentence 5.a. is ambiguous

and that sentences 5.b. and 5.c. are unambiguous and represent

the meanings which are contained in sentence 5.a.

5.a. Flying kites can be exciting.

5.b. Flying kites is exciting.

5.c. Flying kites are exciting.

The question under consideration was at what stage speakers

would perceive the ambiguity of sentence 5.a. The behavior

of the subjects in these experiments contradicted the

theoretically-based assumptions. The subjects in Experiments

I through V indicated that sentences of the types of 5.a.,

5.b., and 5.c. were ambiguous. For these subjects it appeared

that the verb forms is and are were not functioning to dis-

ambiguate the nominal. This behavior was also unexpected.

Roger Brown (1973) has shown that by Stage V, which occurred

in the children he studied by the time they were 3-1/2 years

old, children have reached the criterion of 90 percent correct

usage of the copula and of the third-person singular morpheme










s. Thus, simple subject/verb agreement is acquired very

early by speakers of English.

Apparently, subject/verb agreement in the context of

sentences such as 5.b. and 5.c. was not acquired at such an

early stage. This was tested in experiment six where it was

shown that subjects as old as twelve years had problems with

subject/verb agreement, especially in the context of object

nominals as in sentence 5.b. These problems do not interfere

with communication simply because the context of a conversa-

tion serves to prevent any misinterpretation of the ambiguous

nominal.

The inability on the part of these subjects to handle

subject/verb agreement competently explains why in the first

five experiments the subjects perceived the unambiguous test

sentences as ambiguous. Because they had not clearly acquired

the rules for subject/verb agreement in the context of an

ambiguous nominal, they were incapable of using that syntactic

information to disambiguate the nominal, and, consequently,

they perceived the sentences as ambiguous.














APPENDIX A

SENTENCES FOR EXPERIMENT I


Pretest sentences

1. The cat is lying on the table.

2. Riding horses can be fun.

3. The clown is holding his shoe.

4. Eating popcorn can be messy.

5. The woman is wearing a dress.

Test sentences

1. Playing grownups can be funny.

2. Playing grownups is funny.

3. Playing grownups are funny.

4. He wants to stop smoking.

5. He wants to quit smoking.

6. He wants to prevent smoking.

7. Shooting stars can be exciting.

8. Shooting stars is exciting.

9. Shooting stars are exciting.

10. Sailing boats can be dangerous.

11. Sailing boats is dangerous.

12. Sailing boats are dangerous.

13. Painting horses can be messy.

14. Painting horses is messy.

15. Painting horses are messy.