Toward Understanding Variable Ordering Heuristics for Constraint Satisfaction Problems
نویسندگان
چکیده
Most previous work on understanding variable ordering heuristics for constraint satisfaction problems has focused on the ability to recover from bad decisions. It has been demonstrated however that this ability cannot be the full explanation of the quality of a variable ordering heuristic [8]. In this paper, we develop a more complete framework for analyzing heuristics based on optimal policies. We consider a second policy (in addition to the principle of quick recovery), which we call promise, which is simply to make choices that maximize the likelihood of successful search. We then develop a method for measuring the degree to which a heuristic conforms to the promise principle. Using this measure, we show that variable ordering heuristics vary with respect to their promise, and that for problems with many solutions the degree of promise correlates highly with efficiency of search.
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