Backward highlighting: enhancing faceted search

Directional faceted browsers, such as the popular column browser iTunes, let a person pick an instance from any column-facet to start their search for music. The expected effect is that any columns to the right are filtered. In keeping with this directional filtering from left to right, however, the unexpected effect is that the columns to the left of the click provide no information about the possible associations to the selected item. In iTunes, this means that any selection in the Album column on the right returns no information about either the Artists (immediate left) or Genres (leftmost) associated with the chosen album. Backward Highlighting (BH) is our solution to this problem, which allows users to see and utilize, during search, associations in columns to the left of a selection in a directional column browser like iTunes. Unlike other possible solutions, this technique allows such browsers to keep direction in their filtering, and so provides users with the best of both directional and non-directional styles. As well as describing BH in detail, this paper presents the results of a formative user study, showing benefits for both information discovery and subsequent retention in memory.