Users can then refine their searches based on the paths others have followed.
This retrieval behaviour based approach is reminiscent of collaborative filtering, but there are significant differences. Retrieval behaviour based filtering, on the other hand, passively aggregates implicit user relevance judgements around particular search topics. Furthermore , content analysis, even where possible, can give no indication as to the quality of the content of a document something that is inherently subjective. Furthermore, social filtering systems implicitly locate documents that a user may consider to be 1 high quality since they are based on subjective evaluations amongst similar users. Social filtering implicit assumes that users correlate at the item level.