A Test of the Effectiveness of Sensor Lines Showing Linkages between Displays and Controls 1

This experiment tested the effectiveness of sensor lines (heavy lines drawn on a control panel to show the linkages between displays and controls) on simple panels made up of lights (the displays) and keys (the controls). The three independent variables were (a) size of panel (two sizes were tested), (b) compatibility of the display-control linkages (a maximally compatible and a highly incompatible arrangement were used), and (c) the presence or absence of sensor lines. Eight panels were constructed to test all possible combinations of these three independent variables. Eighty male subjects in all (ten for each panel) were used. The subject's task was to push the appropriate key as soon as a light had been turned on. Each subject was given 240 consecutive trials on the panel to which he was assigned. Dependent measures were: time to first response, time to correct response, and errors. The results show that it is more imporant to make the linkages between displays and controls compatible than it is to use sensor lines which show schematically the linkages between displays and controls. Sensor lines appear to have a limited kind of usefulness for panels of the type tested here: The lines improved performance only when the linkages between displays and controls were not compatible.