[Individual differences in solving spatial problems of the IST and IST-70 subtest on "cube problems"].

Spatial ability is one of the primary mental abilities which has been subject of many empirical studies--especially in the factor analytical research. Analysing the mental processes when solving space tasks, e. g. by means of retrospective verbal reports, two different strategies can be distinguished. The first strategy (called "holistical" strategy) can be described as a mental rotation of the given stimulus, the second one (called "analytical" strategy) is characterised by nontransformal mental processes, e. g. pattern matching processes. In order to identify those different strategies, test items are required, which have different solution probabilities when being solved with different strategies. The "cube tasks" of the IST and IST-70 by Amthauer (1953, 1970) are of this type, as Putz-Osterloh (1977) has found in an experiment. The hypothesis of individual differences in solving space tasks was tested in two different samples. First the "cube tasks" of the IST-70 were administrated to 264 applicants for the pilot job. Data analyses using the mixed-Rasch-model (Rost, 1990) confirmed the hypothesis of an "analytical" and "holistical" strategy. In the second study 2558 pupils of the 7th grade were tested with the "cube tasks" of the IST. A latent class analysis of their response patterns revealed basically the "holistical" and "analytical" strategy and, in addition, four strategies which can be explained by motivational factors.