Two main ideas are proposed in this article. Richard and Tijus (in press) shown that problem solving can be explained by object properties that subjects take into account during the solving process. Stable properties are those which can not be modified by an action (for instance, an object's size, shape, etc.) and unstable properties are those which can be modified by an action (for instance, an object's location). Our purpose is that the problem space (Newell & Simon, 1972) can be described by state properties and that this description permits explaining the subjective distance (in the subject's mind) between two states. We suggest that similarity between state properties guides a subject's search through the problem space and can lead subjects through irrelevant paths. We think that in this condition, the well known beneficial effect of impasse situations consists in the fact that they permit subjects to discover the relevant properties of objects, problem constraints, and goal properties. Two experiments are proposed here. Results obtained in the first experiment show that working on impasse situations before solving the problem improves performance. Results of the second experiment show that working on impasse situations allow subjects to discover the relevant properties of a problem space, and that the benefit can be extended to all problems sharing the same problem space (which naturally contain the same impasses), even if their initial and final states are different. These results shed some light on the beneficial effects of impasses in problem solving.