The book summarizes the application of signal detection theory to the analysis an measurement of humn observer’s sensor sysem. The theory provides a way to analyze what had been called the threshold or sensory limen, the basic unit of all discrimination studies, whether human or animal. The book outlines the theory of statisical decision making and its application to a variety of common psychophysical processes. It shows how signal detection theory can be used to separate sensory and decision aspects of responses in dicrimination. The concepts of the ideal observer and energy detector are presented and compared with human auditory detection data. Signal detection theory is appliced to a variety of other substanditive problemsin sensory psychology. Signal Detection Theory and Psychology is an invaluable book for psychologists dealing with sensory perception, especailly auditory, for psychologists studying discrimination in other cognitivie processes, and for human factor engineers dealing with man/machine interfaces.