Mental visualization before and after problem presentation: a comparison.

ABSTRACT

Three experiments were carried out to study the effects on problem solving of visualization when subjects (secondary-school students and undergraduates) were instructed to generate mental images before the problem was presented and when they received such a hint after being given the problem. In each experiment an arithmetic, a geometric, and a practical problem were presented in three different conditions, a control condition, an "imagery-before" condition, and an "imagery-after" condition. Analysis showed that, in general, the "imagery-after" task helps subjects to overcome the misleading or fixating tendencies which interfere with problem solution; in contrast, the "imagery-before" task may enhance such tendencies.