Current Topics in Qualitative Reasoning

In this editorial introduction to this special issue of AI Magazine on qualitative reasoning, we briefly discuss the main motivations and characteristics of this branch of AI research. We also summarize the contributions in this issue and point out challenges for future research. Successful application areas include autonomous spacecraft support, failure analysis and on-board diagnosis of vehicle systems, automated generation of control software for photocopiers, and intelligent aids for learning about thermodynamic cycles. Qualitative reasoning is thus relevant for researchers who are interested in important AI issues as well as for managers, developers, and engineers who are looking for potential industrial benefits of AI. A decade has passed since the publication of three collections of papers and a book covering the foundations of the field (Weld and de Kleer 1990), the status at that time (Faltings and Struss 1992; Williams and de Kleer 1991), and a comprehensive treatment of qualitative simulation (Kuipers 1994).