Measures of symmetry

Abstract

Three discrimination, rating, and ranking experiments were conducted to test the utility of two new single-form measures of symmetry in predicting response to plane figures. The predictive power of the new measures varied with the type of the perceptual task, prediction being better for tasks of a more clearly perceptual nature. The rest of variance in response was due to poorly defined conceptions of symmetry in many Ss, the confusion of symmetry with compactness, and the overestimation of symmetry in figures that approximate in appearance their ideally symmetric prototypes. These and previously conducted experiments lead to the conclusion that in many instances the symmetry parameter of random polygons has no significant influence on response variance and that, for figures of a given level of complexity, the only practically significant predictor of response is a measure of dispersion of shape contours. © 1971 Psychonomic Society, Inc.