In order for agents and humans to leverage the growing wealth of heterogeneous information and services on the web, increasingly, they need to understand the information that is delivered to them. In the simplest case, an agent or human is retrieving "look-up" information and would benefit from having access to provenance information concerning recency, source authoritativeness, etc. In more complicated situations where information is manipulated before it is returned as an answer, agents and

more »

... mans would benefit from understanding the derivations and assumptions used. When services are involved, users and agents also would benefit from understanding what actions could be or were executed on the user's behalf. In this paper, we introduce a strategy for registering information sources and question answering systems providing support for implementing distributed and cooperative web services. In this paper, we describe the inference web infrastructure that supports explanations in distributed environments such as the web and describe the elements of its registry.