DPT Bridge Library INFO STOPS                                                  

Keywords versus Subjects

Keywords are natural language terms. They are the words and synonyms that define your research topic and its related concepts. They form the basis of exploratory searching in catalogs and databases as you begin your research. Here are some things to note about keyword searching:

• a database will search for keywords in the title, source, and body of the text of each entry
• keyword searching is very flexible as words can be entered in any order
• searches done with keywords tend to be broader
• keyword searches can yield too many and sometimes irrelevant results
• results can lead you to the more relevant subject headings embedded in each entry
  

• subject searching is very specific and searches only in the subject field of each entry
• you need to know the exact subject heading in order to do a subject search
• results are highly relevant to the topic
• many databases use subject headings that are unique and you will need to use a thesaurus to determine the correct subject to use
• Medline's thesaurus is called MeSH and CINAHL uses Cinahl Headings
  

Date and Other Limiters

Limiters are another feature you can use to further tailor your searches. The most commonly used ones are language and years of publication. When searching a database such as MEDLINE which is international in scope you can limit your search results to English only. If you need topical information on recent research studies it is best to limit your search to items published between two years ago and the present.

Other common limiters are types of material - book/video etc. In addition you can specify location as a limiter in the catalog - beatley/reference/periodicals/children's literature etc. To further focus a search you can use specialized limiters such as refereed journals or peer reviewed articles. Some databases will also allow you to limit your search to full text articles only. However not every database has everything in full text so you are only searching a smaller subset when you choose this option.

Boolean Operators

Boolean operators allow you to manipulate your search terms in a way that catalogs and databases understand. The most commonly used are and, or , and not. Used in conjunction with search words and phrases they will change the results returned.

• In a search for information about the effects of a particular drug, the search could be written drug AND interaction. The database will return all the records that contain both words. The more terms you add using AND the narrower your search will be and fewer results will be returned.
• The operator or is best used when searching terms that are synonymous or interchangeable. In a search for treatment OR therapy the database will find all records that have either word or both in them. Often this will make the result set quite large.
• To limit the results to a specific subset of a concept, use NOT. In the following search reading disorders NOT dyslexia the results will contain the phrase reading disorders but any mentioning dyselxia will have been eliminated.

Proximity Operators

Proximity operators show adjacency among search terms. Although each database may use different commands, the most common proximity operators are: NEAR, ADJ(adjascent), and WITH. A keyword search will find you terms randomly in a record. Doing a proximity search tells the database to find each word within a defined proximity. This increases your chance of finding relevant information. Proximity operators tell the database to search your terms near each other, but in no particular order. Sometimes you can add /# ( where # = the number of words) to indicate more exact proximity. Most databases recognize proximity operators. To check on the exact protocols refer to the Help screens. For example: women NEAR/10 colleges tells the database to find the word women within 10 words of colleges. This focuses your search so that both terms may be found either in the same sentence or the same paragraph but ultimately within ten words of each other.

Truncation and Wildcards

Many databases allow the user to substitute a symbol for an alphanumeric character in the search string. This is a helpful feature as it can eliminate the need for long searches with similar words separated by the Boolean operator OR. This symbol is usually called a wild card. The asterisk is often used for this purpose.

• In a search for women's colleges you may want to consider using woman in the singular as part of your search. Instead of using the following search women OR woman AND college as your search you can simply enter it this way wom*n AND college.
• Truncation works in the same way. It searches for words with the same root and their various endings. Searching the term portrait* will return records with portrait, portraits, portraiture etc.