A technique for representing an information need and employing one or more
filters to select documents that satisfy the represented information
need, including a technique of creating filters that involves (a)
dividing a set of documents into one or more subsets such that each
subset can be used as the source of features for creating a filtering
profile or used to set or validate the score threshold for the profile
and (b) determining whether multiple profiles are required and how to
combine them to create an effective filter. Multiple profiles can be
incorporated into an individual filter and the individual filters
combined to create an ensemble filter. Ensemble filters can then be
further combined to create meta filters.