The University of Kansas Libraries
Database Search Techniques
Searching for information in electronic databases can be easy if you remember these principles:
1. Controlled Vocabulary or Subject Searching more information
"Controlled vocabulary" refers to the use of standard terms to describe the contents of the articles in the database of a computer index. Librarians often refer to these standard terms as "subject headings," although the computerized indexes may call them "thesaurus terms" or "descriptors." Each computerized index in the KU Libraries has a specific controlled vocabulary that is all its own. Searching the index using that vocabulary allows you to retrieve all the records in the database on a particular topic using a single search term.
There are a number of ways to access this controlled terminology. Some indexes may have an online list of subject headings, sometimes called a "thesaurus." If the index you are using has a thesaurus, select it, then type in your search term and see if it is in the controlled vocabulary. If the term is not, the index may direct you to the appropriate term to use.
2. Keyword Searching
You do not have to search the electronic indexes using the controlled vocabulary. Instead, you may wish to search for the occurrence of any word or words that to you best describes the information you need. This is called "keyword" searching. This method allows you to search for any word anywhere in a citation or article. Keyword searching is probably the most common method used in searching the wide variety of different electronic indexes and databases available in the KU Libraries.
3. Boolean Searching more information
A research topic often involves more than a single concept. For example, if you are working on a paper dealing with the ethical implications of employer access to private e-mail correspondence of employees in large, multinational corporations you have a number of different concepts: ethics, employer vs. employee rights, privacy, electronic mail, and multinational corporations. A simple subject or keyword search generally allows you to search for one concept at a time. What you may wish to do is a single search that combines all of these concepts in one search statement, hopefully pulling up articles that deal specifically with your paper's topic.
This is where "Boolean" searching comes in. Boolean searching allows you to combine many different concepts in a single search using the "operators"and, or, and not to tie your search terms together. See the "Boolean Searching: An Introduction" guide for examples of how Boolean searching works.
4. Relevance Searching
Relevance searching allows you to enter multiple search terms and to indicate the importance with a symbol. Symbols are usually + (items must contain a term with this symbol) or - ( items must not contain a term with this symbol). The system will search all fields of all records for your term or terms and rank the results using a relevancy algorithm.
5. Truncation and Wild Cards
Most electronic indexes allow the use of "truncation" and "wild card characters." These characters are usually the question mark ?, the exclamation mark !, or the asterisk *. Each database may use a different character. Check the online help or ask for assistance at the Reference Desk if you are not certain which character to use.
"Truncation" allows you to search for a root word and all of its various endings. For example, a search for televis? would retrieve records with the words television, televisions, televise, televised, televising, televisual, etc.
A "wild card" takes the place of letters within a word and is an important way of catching variant spellings. For example, the American spelling is color, the British spelling is colour. To retrieve both spellings, you might search for col*r.
6. Field Searching
Each record in a database is composed of separate fields which contain specific pieces of information. By looking for terms within a certain "field" such as language, year of publication, type of publication, you can limit or define your search more easily. For example, if a database contains records for journal articles, chapters in books, and conference proceedings, and you ONLY want journal literature, you can limit your search to retrieve citations that refer strictly to journal articles. The specific commands you use will vary depending upon the software of the database you are searching. Take a look at the online help, one our printed users' guides, or ask one of the librarians in the reference area for assistance.
7. Proximity Locators
When using keyword searching, you can specify how near one term must be to another and in what order by using the following "proximity locators." These are especially useful when searching full-text databases. Three useful proximity locators are the following:
W/n Finds both search terms in the same document in any order, as long as each term appears within "n" words of the other ("n" is a number that you select).
For example: laser W/10 surgery
finds the word "laser" within 10 characters of the word "surgery"
PRE/n Finds both search terms in the same document but specifies that the first term occur before the second term.
For example: European PRE/2 Community
finds the word "European" 2 characters before the word "Community"