Multiple Representation Perspectives for Supporting Explanation in Context

The term perspective is used for a set of properties describing an object with respect to a common theme. The use of a perspectives representation is illustrated and evaluated in a programming tool called EXPLAINER, which supports programmers by providing explanations of examples related to the programmers’ current task. Having multiple representation perspectives is essential for supporting people working from examples. Namely, it allows explanations of the examples to be generated according to perspectives that accommodate the changing context and needs of the programmers while they explore an example and develop a solution to their task. The multiple representation perspectives and corresponding perspective explanations support the development of a mental model of the example that can then be used in solving the current task. A formal notion of perspectives as named sets of property-value pairs is incorporated in FrameTalk, a frame-based knowledge representation language. It is used to illustrate the representational basis for examples as they occur in the EXPLAINER system. The perspectives mechanism also addresses problems found in term-based knowledge representation languages, problems such as the proliferation of nonintuitive concepts, the misuse of the generalization link as a compositional link, and the differences when using concepts in different application contexts.