In a problem solving experiment, predictions were based upon a theory of motivation and action, the scheme theory, and a psychometric model for the component analysis of rating data, the sector model (Eckblad, 1981; 1980). Pattern guessing tasks were presented to 32 students, 8 to each subject, in individual sessions lasting more than one hour. Number of errors, rated attractiveness, and guessing latencies (the process variables) were recorded during each task. After completion of each task, the affective reaction to it was assessed by means of ratings on six scales, including the scales Pleasant, Interesting, and Complex. On the basis of the sector model, an index of assimilation resistance was computed from the ratings of each task/subject unit, and the index was used to predict mean values and gradients for the process variables. Results show that the sector structure is clearly present in the rating data, that the process variables fit into the structure in the predicted manner, and that mean values and gradients for the process variables differ highly significantly and as predicted among tasks of different levels of assimilation resistance.