Use facets to narrow the initial search set that you get to something more accurate by selecting facets that match for keywords or that point to an aspect of your topic that you identified using the Who, What, Where, When, Why, How exercise.
Facets
Nearly all databases use facets to drill down into the search results after an initial search.
Facets are:
limiters that can be applied within a search result set.
allow you to select a subset of articles based upon criteria that you choose.
Facets include:
Type of Resource
Subject
Author
Date
Discipline or database specific information such as keywords or classification codes.