STUDIES IN THE ACCURACY OF MOVEMENT. III. THE BISECTION AND DUPLICATION OF ANGULAR EXTENTS AS A FUNCTION OF SIZE OF ANGLE AND OF TYPE OF END POINT CUE.
ROCHESTER UNIV N Y DEPT OF PSYCHOLOGY
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This report is the third in a series of studies on the accuracy of movement. Experiments are reported in which subjects N12 turned a 2.5 inch diameter knob through an angular extent and then attempted either to bisect that extent or to duplicate it. The study is concerned with the accuracy and precision of such responses as a function of the angular extent to be bisected or duplicated ranging from 20 to 160 degrees and of the type of end-point cue provided tactual-kinesthetic, visual, or auditory. The results presented as mean average error AE and mean constant error CE showed no significant differences related to type of end-point cue. Size of angle was found to be a highly significant variable. Accuracy and precision increased significantly with increase in angle size, both for duplication and for bisection, with most of the improvement being achieved from 20 to 80 degrees and relatively little from 80 to 160 degrees. For bisection a rather large positive CE over-setting of 25 per cent was found at 20 deg. which remained positive throughout but was reduced to 11 per cent at 160 deg. For duplication a positive CE of 14 per cent was found at 20 deg. but was reduced rapidly and was of zero order for 80 and 160 deg. Author
- Human Factors Engineering and Man Machine Systems