Citation

Green P, Davis G. J. Saf. Res. 1976; 8(4): 180-183.

Affiliation

Green, Paul: U Michigan

Copyright

(Copyright © 1976, U.S. National Safety Council, Publisher Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Pictographic symbols, intended to be recognized at a glance, are being used increasingly to identify automobile controls. A laboratory experiment was conducted to examine certain aspects of the recognition problem. When the knob on which the pictogram appears is rotated. Ten subjects made timed same-different responses to three pairs of standard control symbols differing in orientation. The time required for mental rotation of all symbols was found to be a linear function of angle. There were no significant differences between symbols. The mean rate of rotation, was 130 degrees per second. Since the expected time for this added mental operation is nontrivial, the time available to survey the road ahead is reduced. Consequently, the probability of missing an accident-generating hazard is increased. It is therefore suggested that the symbol standards be modified to require symbols to be displayed only in their perceptually upright positions.