The Relative Operating Characteristic in Psychology
Psychological measurements of an individual's ability to make fine discriminations are often plagued by biasing factors that enter as a covert discrimination is translated into an overt report about it.
Reliable, valid measures are desired of an individual's ability to make a great variety of sensory discriminations, along dimensions such as brightness, hue, loudness, pitch, and the intensive and various qualitative attributes of taste and smell and touch. Sometimes the focus is on the organism's capacity for discrimination, as when the functioning of the sense organs is under study. At other times, interest centers upon the discriminability of the alternatives, as when the measures are used in the development of a product such as color film or tea.
Also sought are accurate measures of more complex perceptual discriminations. How well do individuals judge relative size, distance, direction, time, and motion? How noticeable is a given road sign, and how distinguishable are the signs that employ different combinations of shape, color, and notation to convey different meanings?
Further, it is important to develop unbiased measures of cognitive discriminations, such as those related to memory and conceptual judgment. Psychologists ask people to distinguish objects they have seen before from objects they have not, perhaps nonsense syllables or advertisements; to tell from an article's title, descriptors, or abstract whether it is relevant or irrelevant to a particular need for scientific information; to say whether a given opinion is representative of source A or of source B; and so on.
The translation of covert discrimination into overt report is not direct and simple, according to psychological theory, either because the output of the discrimination process is not definite or because judgmental considerations can