FacetedBrowsing

FacetedBrowsing is one way to use a FacetedClassification system to allow users to find information.
The key elements of a FacetedBrowsing system are that:

* users filter a set of items by progressively selecting from only valid values
* the list of valid values are filtered to only show those that do have results available
* results are displayed as soon as possible
* it is impossible to get an empty result
* any facet can be chosen as a starting point
* it sits on top of a FacetedClassification system
* it does not involve entering keywords