HIGHER-ORDER AND LOWER ORDER VARIABLES IN THE VISUAL-PERCEPTION OF RELATIVE PULLING FORCE

In 7 experiments, undergraduates judged the force exerted by a videota ped standing puller, a computer-generated (stick-figure) puller, or a computer-generated inverted pendulum. Single and stepwise multiple reg ression analyses determined the kinematic variables exploited by the p articipants. Results show that (a) judgments correlated highly with fo rce and improved with feedback; (b) judgments correlated more highly w ith lower order kinematic variables than with force itself; (c) partic ipants differed in the kinematic variables exploited; (d) participants changed over blocks of trials in the variables exploited; (e) some pa rticipants used compound kinematic variables; (f) the variables exploi ted depended on the type of feedback; and (g) judgments to upright pul lers, inverted pullers, and simple pendula showed the same qualitative patterns. Implications for theories of direct perception, directed pe rception, and heuristics are considered.