Scaling estimates of amplitude for movements without visual guidance

Three groups of subjects were involved in estimating movement amplitudes. Two of these groups used the method of estimation, labeling the amplitudes of simple linear movements in inches. One group made active movements, the other experienced passive movement of the arm. The third group, using the method of production, attempted to move the distance required by the experimenter's label. Performance was described in terms of absolute, algebraic, and intrasubject variable error. No striking differences were noted between the three task groups, but males and females differed systematically. Females tended to over-estimate and males to underestimate the distances moved. Lack of evidence for any range effect suggests that subjects were operating from relatively stable perceptual traces, accessed by the verbal labels, rather than from memory traces of previous estimates of the same amplitudes.