PSYCHOPHYSICAL DIMENSIONS OF SIMILARITY AMONG RANDOM SHAPES

Six psychological dimensions were recovered from similarity judgments of 20 random forms using Kruskal's nonmetric scaling technique. These were related to 10 physical factors describing the forms by using canonical correlation analysis and rotations of the resulting vectors. Four factors accounted for 2/3 of the variance of the intersection of the physical and psychological spaces for each of 11 Ss. The factors are described as Complexity, Curvature, Curvature Dispersion, and Straight-length Dispers ion. The problem of the proper psychological distance metric is discussed, and individual differences among Ss are analyzed. The results lead to the conclusion that the four major factors found may be good representations of processes occurring in the perceptual system. © 1968 Psychonomic Society, Inc.