Since filtering is the core and sometimes only interaction technique in traditional faceted browsers, users often find themselves unable to proceed with potentially useful exploration once they have exhausted all filters. When this occurs, they are left with a set of items, from which they must ei-ther remove filters and try new ones, or start a brand new search. This is true even though there are often complex and interesting relationships between items.

To enable users to navigate further into related items whether or not filters have been exhausted, FacetLens offers a new operation we call a pivot. Pivots are a means to reset the view to show related items, enabled by allowing items to be attributes of other items. For example, in the Papers by Author facet, author items are attributes of paper items, but each author attribute bubble also represents an author item in the dataset (Figure 1 and 2).