Distributed knowledge by explanation networks

A knowledge based system may be considered as knowledge, distributed between one or several experts and the system users. Explanations in such a system provide for a more intensive interaction between the system and the user. We construct an explanation network by defining relationships between various knowledge fragments. Knowledge fragments on varying levels are formulated using the Qualitative Process Theory. The relationships are defined by links, compatible with Rhetorical Structure Theory. Different knowledge elements are combined into an explanation path by using Toulmin´s argumentation theory. The feasibility of this approach is investigated. We show the following: By representing relations in a concept hierarchy as well as representing the relationships between elements in a rule of a knowledge base, both problem solving inferences and explanations can be generated. At the moment, the derivation of explanations cannot be performed automatically, but ready-made explanations may be stored and presented in a useful way. The explanation network idea has great knowledge acquisition power. An empirical study with users showed that different paths within the explanation net are useful for users with different prior knowledge. To conclude, the idea of distributing knowledge by support from an explanation network is fruitful and feasible.