So far, the techniques mentioned in this chapter represent individual approaches to integrating navigation and search that you can merge into an existing web site. The faceted browse interface, on the other hand, which is a system for navigating large bodies of information developed by researchers at the University of California, Berkeley, offers a more holistic integration of search and browse.
This interface relies on facets and faceted classification as a means of structuring information (see Chapter 9). Facets offer an alternative to hierarchical structures. Instead of creating a tree structure and fitting items into that structure, facets seek to describe the properties of a thing.
A facet is nothing more than a category. But it's the arrangement of categories that is important in faceted classification. Facets are mutually exclusive dimensions or properties of the object they describe. Facet categories then have values within each. Unlike hierarchies, these values from different facet categories aren't structurally related to one another. Facet categories can be thought of as independent buckets of values. This allows for any number of ways to approach the objects in a collection.
The classic example for explaining facets is with bottles of wine. There might be several key properties by which to describe wine, such as Region, Type, and Price. Each of these is a mutually exclusive facet. For instance, the values under Region aren't dependent in any way on ...