The quantitative study of shape and pattern perception.

The pre-eminent importance of formal or relational factors in perception has been abundantly demonstrated during some forty years of gestalt psychology. It seems extraordinary, therefore, that so little progress has been made (and, indeed, that so little effort has been expended) toward the systematizing and quantifying of such factors. Our most precise knowledge of perception is in those areas which have yielded to psychophysical analysis (e.g., the perception of size, color, and pitch), but there is virtually no psychophysics of shape or pattern. Several difficulties may be pointed out at once: (a) Shape is a multidimensional variable, though it is often carelessly referred to as a "dimension," along with brightness, hue, area, and the like, (b) The number of dimensions necessary to describe a shape is not fixed or constant, but increases with the complexity of the shape, (c) Even if we know how many dimensions are necessary in a given case, the choice of particular descriptive terms (i.e., of referenceaxes in the multidimensional space with which we are dealing) remains a problem; presumably some such terms have more psychological meaningfulness than others.