Unnoticed hints facilitate representational change in problem solving

We conducted an experiment to examine whether the solution to insight probl ems is facilitated by unnoticed hints. Our theoretical basis is a model pro posed by Ohlsson (1992), where insight is conceptualized as a change of the problem representation that follows an impasse. In previous studies (Knobl ich, 1997) we found empirical evidence for two processes of representationa l change, constraint relaxation and chunck decomposition. The present exper iment aimed at finding out whether the representational change caused by th ese processes can be accelerated by shortly presented hints. Two groups of subjects were compared. The first group was presented with an extremely sho rt hint (17 msec, masked) during problem-solving, while the second group re ceived no hint. In phases of problem-solving, where subjects normally encou nter impasses, hints increased solution probability selectively for tasks r equiring constraint relaxation to be solved.