Selection of search phrases to suggest to users in view of actions performed by prior users

A search engine system uses information about historical query submissions to a search engine to suggest previously-submitted, related search phrases to users. The related search phrases are preferably suggested based on a most recent set of query submission data (e.g., the last two weeks of submissions), and thus strongly reflect the current searching patterns or interests of users. In one embodiment, the related search phrases are scored and selected for display based at least in-part on (a) a frequency with which each search phrase has been submitted, and/or (b) an evaluation of the "usefulness" of each search phrase, as reflected by actions performed by prior users while viewing corresponding search results.