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Introduction to Database Searching powerpoint presentation ( PPT )
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Introduction to Searching Bibliographic Databases Jennifer Lyon, M.S., M.L.I.S. Clinical Research Librarian Health Science Center Libraries University of Florida
A database is an organized collection of data. Bibliographic databases are searched through many of the same techniques as any other database Focus will be on PubMed, but these techniques apply to ANY literature database
Examples of Records and Fields Record # Author Title Publisher Date of Publication 1 Jones KM Infectious Diseases Wiley 2001 2 Smith BR Medicine Cambridge Univ. Press 2004 3 Johnson AS Cancer Elsevier 2005 4 Bradley PL Asthma Synergy 2003
Examples of Records and Fields Record # Author Title Publisher Date of Publication 1 Jones KM Infectious Diseases Wiley 2001 2 Smith BR Medicine Cambridge Univ. Press 2004 3 Johnson AS Cancer Elsevier 2005 4 Bradley PL Asthma Synergy 2003 RED=RECORD BLUE=FIELD PURPLE = ONE PIECE OF DATA
Searching a Database Different search interfaces do the same things in slightly different ways Good search interfaces should provide Ability to search for a specific item Ability to search for related items to a known item Ability to search in a specific field or fields Ability to combine search terms using Boolean Logic Ability to retrieve search results in a useful way
Step by Step Procedure Asking and Parsing the Question Understanding Boolean Logic Understanding Database Structure Understanding Field Searching Understanding Controlled Vocabulary Controlled Vocabulary vs Keyword Searching Specialty Features Putting It All Together
Asking the Question: PICO Patient, Population or Problem What are the characteristics of the patient or population? What is the condition or disease you are interested in? Intervention or exposure What do you want to do with this patient (e.g. treat, diagnose, observe)? Comparison What is the alternative to the intervention (e.g. placebo, different drug, surgery)? Outcome What are the relevant outcomes (e.g. morbidity, death, complications)? http://healthlinks.washington.edu/ebp/pico.html
Parsing the Question What are the main concepts in your question? Sample question: Does nutrition therapy improve decubitus (pressure) ulcer healing in an elderly patient? Concepts: Nutrition therapy Decubitus/pressure ulcers Ulcer healing Elderly patients Treatment efficacy
Boolean Logic A British mathematician named George Boole (1815 1864) developed an algebraic system of logic that is now widely used in computer and electronic systems including database searching. very simple form of Boolean Logic is used for searching most bibliographic databases.
Boolean Operators Standard Boolean Logic for database searching uses 3 relationships among search terms. AND OR NOT It is both simple and powerful.
AND BOTH terms included in any results. If a record has only one of the two terms, it will not be retrieved. If the record has neither term, it will not be retrieved. What does this do to the amount of records retrieved?
OR Only one ( NOT both ) of the terms are in the results record if both are included. What does OR do to the amount of records retrieved?
NOT Excludes any results containing the term Records containing both will not be retrieved. What does NOT do to the amount of records retrieved?
Using OR idea/concept and are usually put in parenthesis (term OR term OR term) where all terms are difference ways of representing the same concept (faculty OR teachers OR professors) (students OR learners OR pupils)
Using AND ideas/concepts and can combine OR groupings Term AND (Term OR Term) where each represents a different concept heart attack AND smoking Diabetes AND exercise Cancer AND (treatment OR therapy)
Using NOT often used to get rid of a common subgroup Students NOT dental Diabetes NOT juvenile
Putting Them Together 1. Identify the concepts (Parse the question) 2. List specific terms for each concept 3. Put the terms for each concept in an OR statements within parentheses 4. Combine OR statements with AND 5. Add any NOT statements to the end
Creating a Boolean Search Concept 1 Influenza Concept 2 Vitamin C Concept 3 Treatment Concept 4 helpfulness Influenza Vitamin C Treatment Outcome Flu Ascorbic acid Therapy Recovery Orange Juice Management Success QUESTION: Is Vitamin C helpful in treating the flu? 1. Identify concepts and list terms
Step 2 2. Make your OR statements, one per concept (influenza OR flu OR orthomyxovirus) (vitamin C OR ascorbic acid OR ascorbate) (treatment OR therapy OR management) (outcome OR recovery OR success)
Steps 3 and 4 (influenza OR flu) AND (vitamin C OR ascorbic acid OR orange juice) AND (treatment OR therapy OR management) AND (outcome OR recovery OR success) 4. Consider any NOT statements you might want to add.
Parsing a Boolean Search (emergency OR acute OR critical) AND (treatment OR therapy OR management OR care) AND (motor vehicle accident OR car crash) NOT (pedestrian OR walking ) What are the four concepts? What terms are used for each concept? Which three concepts must be included in all records found? Which concept must not be included in any record found?
Beyond Basic Boolean Field Searching Controlled Vocabulary Subject vs. Keyword Searching Specialty Features Truncation Phrase searching
Field Searching Almost all databases will provide you with some ability to search a specific field or fields. Allows faster searching Allows more accurate searching Not all databases may make all fields searchable. Each search system will require a specific format.
All Field vs. Specific Field Searches I would like to find articles by John Smith. Search all fields: John Smith Search Author Field only: John Smith I would like to find an article published in 1997. Search all fields: 1997 Search Publication Date Field: 1997 Why waste time searching for a date in the author field or an author in the volume field?
Formats for Field Searching Different databases provide different formats for specifying fields. Most use field names or nicknames which may follow a period or be placed in brackets or parentheses. Some databases offer forms or drop down menus.
PubMed Field tags go in  and follow term Field tags can be used within Boolean queries
PubMed Field Tags http://www.ncbi.nlm.nih.gov/books/bv.fcgi? rid=helppubmed.section.pubmedhelp.Sear ch_Field_Descrip [au] = author [ti] = title [tw] = textword [tiab] = title and abstract [mh] = medical subject heading [dp] = date of publication [la] = language [gr] = grant number [ta] = journal name [ad] = affiliation
OVID databases require field tags to follow the term separated by a period. Meharry.in and 2005.yr
Science (Science Citation Index Expanded) provide forms to fill out. Select Field from drop down menu Select Boolean Operator
Combining Field Searches Multiple field searches can be combined using Boolean logic. Find a 2005 article by an author named Hubble about ankle fractures. Combine with AND: 2005 in date/year field Hubble in author field Ankle fractures in title field 2005[dp] AND Hubble[au] AND ankle fractures[ti]
Final Notes on Fields Each database provides its own specific fields Each database requires a specific format to designate field searching When searching a new database, take a moment to read the help documentation; most will provide a list of fields and how to search them.
Controlled Vocabulary A controlled vocabulary is a set of established terms where every term represents a single concept only one term is used for that concept
Another example How many words could you think of for the idea Articles in a database All three articles are about types of cancer but different terms are used in titles.
In a controlled vocabulary ONE word ( i.e., cancer) is chosen and placed in a special field, usually called a subject field. For all three articles subject field by database indexers. Now, Searching the database for cancer in the subject field will identify all records about the concept of cancer even if a different word for cancer is used. in subject in title find?
Structure of Controlled Vocabulary Broader Concepts Narrower Concepts
More on Controlled Vocabulary terms beneath the searched term some subject terms are considered the major focus; you can select to return only those articles. Hip fracture[majr] = only give me articles where hip fracture is an important concept
Subject vs. Keyword Searching Controlled vocabulary searching Matches terms against a specific field in the record. You need to consult a thesaurus (paper or online) to find out what the controlled vocabulary term is for each concept. Free text (keyword) searching Some concepts have many synonyms. A free text search statement would mean "OR"ing all those terms together Matches terms against words anywhere in record (abstract, title, etc.).
Advantages to Controlled Vocabularies Using the controlled vocabulary can make your search more precise and easier. Increases the relevancy of results (fewer false drops) The indexers have already done much of the work for you. Searchable tree structures of terms can help you find new terms to use.
Problems with Controlled Vocabularies NOT all databases use a controlled vocabulary New concepts take time to be added There is often a lag phase during which the Controlled vocabularies can contain some very strange things and some concepts may not be handled well The controlled vocabulary must be easily searchable particular controlled vocabulary can give you a big headache!
Combining Subject and Keyword Searching To be comprehensive, it is often helpful to combine subject and keyword searching (diabetes mellitus[mh] OR diabetes[tw]) (sickle cell anemia[mh] OR sickle cell anaemia[ti])
Boolean logic to combine terms Use of other search fields in combination with subject terms A Complex Search: (head[mh] OR head[tw]) AND (wound and injuries[mh] OR trauma[ti] OR injury[ti]) AND 2005[dp] AND English[la]
Some Specialty Features Truncation Phrase searching Neighboring and other rarer Boolean operators
Truncation What about including the singular and plural versions of words as well as other word variations? For example: therapy, therapies, therapeutics, You could combine them all in an OR relationship: (therapy OR therapies OR therapeutics OR therapeutic) But an easier way is by the use of truncation. therap* Each database handles truncation in a unique way.
More on Truncation Some examples: Bacter$ Proc* Vir? Staph? Be cautious when truncating! If the word stem is too short, there may be too many possible variations and you might pick up unrelated terms. For example, using proc* for finding procaine like drugs will also include words like proceedings and process.
Phrase Searching Sometimes you want to force the database to search for a set of words in exact order Most databases will accept a phrase in quotes. automatically break them up ing the terms Check how the database handles phrase searching before doing it!
Limits Options that make it easier for you to select common options such as language, article type, publication dates, human or animal, gender, age groups, etc. field tags, but sometimes limit pages save time
PubMed Limits Page
Step By Step Search Construction 1. State the question 2. Identify the concepts in the question 3. For each concept, determine keywords and subject terms 4. Specify field tags after terms if needed 5. parenthesis 6. 7. Put any NOT terms at the end Keep track of your searches, how many articles were found total, and how many you selected as relevant