Jean-pran~ois Richard S~bastien Poitrenaud and Charles Tijus

A general model of problem-solving processes based on misconception elimination is presented to simulate both impasses and solving processes. The model operates an goal-related rules ond a set of constraint rules in the farm of “IF (state or goal), DO NOT (Action)” for the explicit constraints in the instructions and the implicit constraints that come from misconceptions of legal moves. When impasses occur, a constraint elimination mechanism is applied. Because successive eliminations of implicit constraints enlarge the problem space and have an effect on planning, the model integrates “plan-based” and “constraint-based” approaches to problem-solving behavior. Simulating individual protocols of Tower of Hanoi situations shows that the model, which has a proper set of constraints, predicts a single move with no alternative on about 61% of the movements and thot protocols ore quite successfully simulated movement by movement. Finally, it is shown that many features of previous models are embedded in the constraint elimination model.