Using Categories to Improve Search
http://home.earthlink.net/~searchworkshop/docs/Search%20UI%20Wkshop-revised_cutrell.pdf

Cutrell, Edward and Susan Dumais
Earthlink
2003

Abstract:

The authors explore ways in which categories can be leveraged to improve search. An interface named SWISH is presented, in which search results are automatically categorized, and pages in the same category are grouped together.