Berthe Y. Choueiry and Toby Walsh

The Fourth Symposium on Abstraction, Reformulation, and Approximation (SARA) took place at Horseshoe Bay Resort and Conference Club, Lake LBJ, Texas, from 26 to 29 July 2000, just prior to the Seventeenth National Conference on Artificial Intelligence (AAAI-2000) conference in Austin. Previous SARA conferences were held at Jackson Hole in Wyoming (1994); Ville d'Esterel in Quebec (1995); and Asilomar in Monterey, California (1998). The symposium grew out of a series of workshops on abstraction and approximation and on reformulation that had taken place alongside the American Association for Artificial Intelligence (AAAI) conference since 1989. SARA is a meeting with an unusually broad subject area. From the earliest days of AI, abstractions and problem reformulations and approximations have been recognized as central to AI for reasoning effectively in complex domains.