Performance and verbally expressed understanding of the principle in the Water-level Task

The present study focused on the question of whether the verbally expressed understanding of the principle of the water-level task is related to task performance and what temporal relation is. Furthermore, the association between the ability to state the principle of the water-level task verbally and performance on other types of spatial tasks (mental rotation and embedded figures task) were analyzed. Subjects participating in the present longitudinal study were 508 children and adolescents of grades 2 to 10, Based on binomial mixture analyses, three subgroups showing different response behaviors on the water-level task were distinguished: (a) bottom parallel, (b) randomlike, and (c) correct responders. The results show a high probability of correct task solutions for subjects with a verbally expressed understanding of the water-level principle. This was not only true at the same time of measurement, but also later in that knowledge of the principle enhance performance. Furthermore, verbal knowledge about the principle of the water-level task is related to the performance on other types of spatial tasks.