The timing of responses to spatial perception-questions

Examination of the time of response to single problems in spatial perception suggests that the approach of subjects to multiple-choice questions may differ from their approach to free-choice questions. There is some evidence for thinking that the slower subjects score more highly, and that practice in a given type of problem affects speed rather than correctness of response. These results may provide a new interpretation of some effects previously observed in repeated retesting of the same group.

The design of the experiment discussed was a “balanced incomplete block”, in which 120 subjects were required to answer 108 out of the total of 540 problems.