person type by faceted activity type is a collection of collections. Each element is an instance of type of person classified by activity that itself has been faceted in at least one way. This collection, which facets person,can be used to generate English questions to aid classification in a clarification dialogue. To make the interface user-friendly, the range of answers to these questions should be small. Since this collection currently (01/00) has fewer than 20 elements, it will be more useful than the faceting of person by type of person classified by activity, which has over 800 instances. See Note About How Facet Assertions Are Used.