Movement compatibility for circular display and rotary controls positioned at peculiar positions

This experiment studied strength and reversibility of direction-of-motion stereotypes and response times for a circular display with rotary controls located at peculiar positions. The effects of pointer position, instruction of turn direction, and control plane on movement compatibility were analyzed using the quantitative measures of "strength" and "reversibility index" for stereotypes. Comparisons were made between the results obtained for peculiar control positions in this experiment with those in which controls were positioned in commonly used planes. Very strong and significantly reversible clockwise-for-clockwise (CC) and anticlockwise-for-anticlockwise (AA) stereotypes were obtained at the 12 o'clock pointer position when the control was positioned in the normal (conventional) and receded frontal planes. Response times were found to be generally longer when there were no clear movement stereotypes. While the CC and AA preferences were dominant and reversible at all planes and pointer positions for normal control positions, there were great variations in strength, reversibility, and type of stereotype found for the different test configurations of the peculiar control positions used in this experiment. Reversed stereotypes of lower strength and weaker reversibility were found for the controls on the bottom and left saggital planes. The results were explained by the fact that a combination of different principles, viz. CC, AA, clockwise-for-right (CR), anticlockwise-for-left (AL), clockwise-for-anticlockwise (CA), and anticlockwise-for-clockwise (AC), were operating at different pointer and control positions. The findings suggested that for improved performance, industrial designers should avoid placing rotary controls at peculiar positions, the normal frontal plane is the best plane for positioning rotary control with circular display, and it is recommended that the pointer is always positioned at 12 o'clock for check reading or resetting purposes. Relevance to industry This study examined population stereotypes and response times of subjects in manipulating rotary controls positioned at peculiar positions with circular displays. The results help to establish guidelines for the industrial design of control panels used in person-machine interfaces to improve human performance. (c) 2006 Elsevier B.V. All rights reserved.