Problem-solving Method Reuse and Assembly: From Clinical Monitoring to Traffic Control

In the knowledge engineering field, models of expertise present interesting properties for reuse. In particular, Problem-Solving Methods (PSM), that identify generic lines of reasoning with specific uses of knowledge types, are good reusable components for knowledge modeling. In this paper we present a case study of PSM reuse, where we focus on two particular issues: (1) how to reuse a PSM by generalizing some of its task assumptions, and (2) the formulation of a new PSM by assembling simpler PSMs. The case study starts with a PSM called Knowledge Based Temporal Abstraction that was originally defined for the clinical domain. We show how to reuse it for a new task in the traffic domain: first, the temporal dimension on which the method is referred is generalized into a linear dimension in order to make abstractions for both temporal and spatial dimensions and, second, a new method for spatiotemporal abstraction is defined by assembling two different PSMs. In summary, the paper underlines and illustrates some of the significant steps for PSM reuse, and it proposes a modular organization of ontologies (using is-a and part-of relations) to facilitate this activity.