Here's a sample research question:
"Do medical students benefit from peer mentoring?"
A possible search phrase could be:
students, medical AND peer group AND (mentors OR teaching OR learning)
Like to know how to get your searches to be short and to the point?
(1) Think of how you can break your research question into multiple concepts
(2) Connect the concepts with the appropriate Boolean operator (AND, OR, NOT - these must be capitalized)
AND - connects different concepts
OR - connects synonyms / similar concepts
NOT - excludes a concept / word
(3) Find the Medical Subject Heading (MeSH) terms assigned to an article
* MeSH terms are assigned to every article in PubMed to help classify the topics of a paper
* Select the Citation Display of an abstract to see the MeSH terms for that article
(4) Use MeSH terms to build more complex searches