HS 307 - Evidence Based Research Methods in Health Sciences: Searching

The Search

Planning a Search

Once you have chosen the database you are going to search, it is time to start thinking about how you are going to go about it.

Start by breaking down your research question into its major concepts.  

Example: Does the use of Interferon therapy improve treatment outcomes for Melanoma patients.

Concepts: Interferon therapy, treatment outcomes, Melanoma

Next think of alternative ways to describe these concepts:

Example: Interferon therapy -> IFN, IFN Therapy, Immunotherapy, Immunosuppression

You will use these concepts as search terms by combining them to find articles that meet your research interest.  

A good strategy when searching is to start with a broad search and then use limiters and subsequent searches to narrow your results.  Below are some helpful tips to keep in mind when searching library databases.

Search Strategies

Keyword Searching

Keyword searches of databases will perform a search of the entire bibliographic record and the full text of the article where possible.  This means that keyword searches will return the broadest possible results and it is possible to become overwhelmed with unrelated results.  Fortunately you can combine keyword searches with more restrictive criteria to help control the results of your search. 

Example: Searching for the phrase Cormac McCarthy as a keyword will return articles written by him, articles written about him, and even articles specifically excluding him if the author mentioned him by name.

Specific Phrases

If you want to search for a specific phrase then place that phrase in quotes when keyword searching.  

Example: Dungeons and Dragons will show results for the popular game but also anything which deals with dungeons and dragons more generally.  Searching "Dungeons and Dragons" will produce results where that specific phrase appears as written and will help narrow results to the game.

Boolean Operators

AND - Using AND will show results where both search terms appear.  This narrows your search

OR -  Using OR will show results where either search term appears. This broadens your search

NOT - Using NOT will exclude a search term from your results.  This narrows your search

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Controlled Vocabulary

Authors refer to ideas in a number of different ways.  Authors from different countries might spell the same words differently.  Word meanings might change throughout time or with advancements in a field.  Or an author might refer to an idea without ever explicitly using a word to describe it.  This can make searching for information difficult to do reliably.  Should you search for information on Bell's Palsy by searching for Bell Palsy or Bell's Palsy?  What about facial palsy or facial paralysis?  Do you have to think of every conceivable way to describe an idea in order to make sure you are getting the results you need?   NO!  Databases account for this issue by using a "Controlled Vocabulary" to describe the included records.  Often referred to as "Subject Terms" or "Major/Minor Headings", these vocabularies might vary from database to database, but will be applied consistently within a given database.  By utilizing the controlled vocabulary when searching, the researcher ensures that they access all available content on a given topic within the database.  And by combining these terms with Boolean Operators, it is possible to create very specific searches which quickly address a given research question.

Limiters

After running your search you will likely be presented with more results than you can practically look through.  This is a great time to start applying limiters.  In the search results you will find relevant limiters on the right hand column.  Applying limiters will refine your existing search results making it more manageable and more relevant.

Citation Tracking

Once you find an article, it may be helpful to check the bibliography for works the author cited.  When possible it is also helpful to check for articles which have cited this article as well.

Troubleshooting

If you are not finding the results you expect take a moment to double check the scope and coverage of the resource you are searching.  It might also help to Broaden or Narrow your search.

Broaden Your Search

When you are not finding enough results consider broadening your search by:

  • Adding similar or broader terms using the OR operator which might include your topic.  Example: "Ultraviolet Rays" OR Sunlight
  • Remove overly specific concepts like specific places, specific times, or specific groups
  • Use keyword searching instead of subject searching 

Narrow Your Search

When you are getting too many results consider narrowing your search by:

  • Adding the AND operator to restrict the pool of results.  Example: Peanut butter AND Jelly
  • Adding the NOT operator to exclude results.  Example: Martin Luther NOT King
  • Adding quotation marks to specific phrases of keyword searches. 
  • Select narrower subject terms.  Example: Use Dementia, Vascular in place of Dementia.

Help!

Need Help?

We would love to help you with your specific questions on this and any future projects you are working on.  If you'd like to get help from a librarian please Ask Us.