A lot of work in constraint satisfaction has been focused on finding solutions to difficult problems. Many real life problems however, while not extremely complicated, have a huge number of solutions, few of which are acceptable from a practical standpoint. In this paper we will present a value ordering heuristic that attempts to guide the search towards solutions that are acceptable. More specifically, by considering the weights assigned to values and pairs of values, the heuristic will guide the search towards solutions for which the total weight is within an acceptable interval.
Tudor Hulubei, Eugene C. Freuder