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Survival Guide for Scholarship, Dissertations, Theses, and Scholarly Projects

Boolean Operators


Putting the Search Together


Use AND to join the different ideas in your topic together and get articles that talk about both topics:

‚Äčstroke AND rehabilitation


Use OR to join synonyms or word variations together to get all of the articles that use any of those words:

rehabilitation OR recovery of function

AND - OR Together

When you want to search using both AND and OR, put parentheses around the OR statement:

stroke AND (rehabilitation OR recovery of function)

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Keywords and Subject Headings


When you search with keywords, you are trying to find words that authors have used in their titles and abstracts or somehow otherwise appear in the article's entry in a database. Therefore you need to brainstorm all of the possible ways authors could refer to your concept:

"endurance" OR "physical fitness"

"education" OR "training" OR "school" OR "learning"

Subject Headings

You can also search using subject headings. Subject headings are keywords assigned by the databases to describe the concepts in an article and to try to take some of the guesswork out of the job of coming up with keywords. Try searching with subject headings and see how your results differ from searching with just keywords.

Still unsure about subject headings? Watch this video for another explanation as well as tips on how to find them.

Interested in text tutorials? Click the PDF links below:


Asking an answerable clinical question...and making your database searching much easier in the process.

Use PICO(T) template below to craft your question. Then use PICO(T) Method for Asking Good Clinical Question to help develop your own topic.

Modifying an Unsuccessful Search

If you aren't happy with the list of articles your search brings back, here are some ways you might think about changing your search.

1. Too many articles / Articles aren't on topic

  • Make your topic more specific. You could add words, using the AND connector, to describe the
    • population
    • setting
    • treatment or intervention
    • outcome
  • Make the ideas within your topic more specific. For example
    • "women" becomes "women over 50"
    • "analgesic" becomes "opioid"
    • "recovery" becomes "length of stay"

2. Too few articles

  • Make your topic less specific
    • focus on the core ideas (remove unnecessary details)
    • choose less specific terms ("exercise therapy" becomes "exercise")
  • Look for different search words 
    • brainstorm synonyms (e.g. "length of stay" = "hospital stay") or different forms of a word (e.g. therapy, therapies, therapeutic) and then use the OR connector to add them to your search.
    • scan abstracts and subject headings to find out which words authors and databases are using to describe your topic.

Photo by Anant Nath Sharma, used with permission under a Creative Commons license