PICO (alternately known as PICOT) is a mnemonic used to describe elements of a good clinical question. It stands for:
P: Patient/Population/Problem
I: Intervention
C: Comparison
O: Outcome
Many people find that the PICO process helps them clarify their question, which in turn makes it easier to find an answer.
Use PICO to generate terms - you'll use some of the terms in your literature search for the current best evidence, and you'll use them in evaluating the information you do find.