Searching Complex Data Without an Index.

We show how query-specific content-based computation can be used for interactive search when a pre-computed index is not available. Rather than text or numeric data, we focus on complex data such as digital photographs and medical images.  We describe a system that can perform such interactive searches on stored data as well as live Web data.  The system is able to narrow the focus of a non-indexed search by using structured data sources such as relational databases.  It can also leverage domain-specific software tools in search computations.  We report on the design and implementation of this system, and its use in the health sciences.