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Information Literacy: Using library databases

What you need to know to do research at the college level.

1. What is a library database? (View four tutorials on this tab.)

  • Library databases provide articles from published works. (e.g. magazines, newspapers, scholarly journals, encyclopedias, and books) These sources are edited by editors and experts in various fields.
  • Libraries purchase databases to serve the information needs of their specific user base,  just as libraries have always purchased print materials for their users. Access is provided on Library Websites with user logins.
  • Databases vary by topics covered and types of information provided. Some cover a broad range of topics, some cover specific topics, some provide one or two types of information and some provide a mix of several types.
  • Most databases provide the full content (full-text) of articles or eBooks, including ways to sort results, and print, download or email the full content.
  • Full-text files are provided in two formats: HTML (Web files) or PDF (scanned images of pages). Some databases provide full-text in only HTML format, and some databases provide a mix of one or the other or both formats.
  • Databases provide the complete source information for citations. Some databases provide machine-generated citations in MLA, APA, and other styles. Be aware of specific style rules in order to check the accuracy of any machine-generated citations.

2. Generating search terms for topic searches

After selecting a database that is appropriate for your topic or information need, figure out the best search strategy for your chosen database. Always read the database descriptions and view any tutorials provided.

3 - 4. Constructing searches using AND, OR, NOT

View two tutorials: 3. Searching effectively using AND, OR, NOT 

                                   4.  Combining AND, OR, NOT (advanced)

Summary: Library databases generally handle connecting words AND, OR, NOT in these specific ways:

  • Use AND between words when both (or all) words must be in the results, for example: 

cats and dogs and birds    Result: ALL three of these words must be present in each search result. Using AND has the effect of narrowing search results.

  • Use OR between words when either (or any) of the words are needed in the results, for example: 

cats or kittens or felines    Result: ANY of the three words are present in search results. Using OR has the effect of broadening search results. The best use of OR is whenever there are two or more words with similar meanings and any of these words will work in the search results.

  • Use NOT between words when a word is causing the wrong information and needs to be eliminated from search results, for example:

cats not dogs    Result: The first word (cats) is present in each search result but the word following NOT (dogs) is eliminated from results, even if the first word (cats) was also present in that result. Use of NOT is tricky. You could eliminate something you want!  

  • When using two or three connectors: Use parentheses ( ) around words connected with OR when combining with AND and NOT, for example:

(cats or kittens or felines) and (care or feeding) not birds   Result: Any of the words inside the first parentheses combined with any of the words inside the second parentheses are in the search results. All results containing the word following NOT (birds) is omitted no matter what other words are present.  This technique is called "nesting." It tells the search engine in what order to combine words.

This use of AND, OR, NOT is called Boolean logic, after George Boole, the mathematician who invented it. Most of the library databases (the library catalog, all Ebsco databases, and others) understand the use of AND, OR and NOT to connect keywords and phrases. Some databases behave differently, so check the help pages to see how they work.

Just ASK!

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