When you run a literature search, if you are extremely lucky, you'll quickly discover the relevant Subject Headings, and when you combine sets, you'll magically come up with 30 perfect articles!

But in real life, that rarely happens. More often you'll run a search and either come up with hundreds or even thousands of results, or you'll come up with zero results. In either case, you'll need to be able to draw upon your knowledge of the search techniques covered in this research guide to finesse your search so that it will bring up the literature you need to answer your research question.

TOO MANY RESULTS!

When your first attempt bring up too many results, try one of these strategies to simultaneously reduce the numbers of hits, and focus the results:

• add another search term, using the Boolean operator AND to make a smaller set
• search on a more specific term
• in databases that offer this feature, such as MEDLINE, restrict your search to MeSH Major Topic (aka Major Concept or Focus)
• in databases that offer this feature, add one or more subheadings
• apply one or more limits (filters), such as publication date, article type, or age group
• when available, deselect the Explode feature, and search only on the more general term, or choose a more specific term on which to search

TOO FEW RESULTS!!

Too few results can be a problem indeed! Here are some tactics to try:

• check your spelling!
• remove one or more terms from your search query
• search on related terms or synonyms, combining terms using the Boolean operator OR to make a larger set
• substitute a more general term
• remove filters, or apply them incrementally
• when available, use the Explode feature to search on narrower terms as well as the more general term
• remove the MeSH Major Topic (aka Major Concept or Focus), if applied