signal detection theory

Also found in: Acronyms.

Signal detection theory

A theory in psychology which characterizes not only the acuity of an individual's discrimination but also the psychological factors that bias the individual's judgments. Failure to separate these two aspects of discrimination had tempered the success of theories based upon the classical concept of a sensory threshold. The theory provides a modern and more complete account of the process whereby an individual makes fine discriminations.

The theory of signal detection has two parts of quite different origins. The first comes from mathematical statistics and is a translation of the theory of statistical decisions. The major contribution of this part of the theory is that it permits a determination of the individual's discriminative capacity, or sensitivity, that is independent of the judgmental bias or decision criterion the individual may have had when the discrimination was made. The second part of the theory comes from the study of electronic communications. It provides a means of calculating for simple signals, such as tones and lights, the best discrimination that can be attained. The prediction is based upon physical measurements of the signals and their interfering noise.

This opportunity to compare the sensitivity of human observers with the sensitivity of an “ideal observer” for a variety of signals is of considerable usefulness, and of growing interest, in sensory psychology. Signal detection theory has been applied to several topics in experimental psychology in which separation of intrinsic discriminability from decision factors is desirable. Included are attention, imagery, learning, conceptual judgment, personality, reaction time, manual control, and speech.

The analytical apparatus of the theory has been of value in the evaluation of the performance of systems that make decisions based on uncertain information. Such systems may involve only people, or people and machines together, or only machines, Examples come from medical diagnosis, where clinicians may base diagnostic decisions on a physical examination, or on an x-ray image, or where machines make diagnoses, perhaps by counting blood cells of various types.

signal detection theory

[′sig·nəl di′tek·shən ‚thē·ə·rē]
A theory which characterizes not only the acuity of an individual's discrimination but also the psychological factors that bias his judgment.
References in periodicals archive ?
The data have been generated using standard protocols within signal detection theory.
The amount of information that is transmitted by a warning system that has certain characteristics in terms of signal detection theory will change if the probability of the occurrence of a malfunction changes.
Donaldson & Glathe (1969) used signal detection theory measures of recognition for lists of digits.
Human factors methods, especially signal detection theory (SDT), can be used to diagnose performance problems, reduce threats, improve security officer morale, and save time and money.
Reflecting a variety of disciplines and approaches, these eight articles were selected from those presented at the symposium of April and May 2003 and include such topics as using signal detection theory as a model to evaluate release and retention criteria in alpine skiing, methods for improving alpine rental operations, contrast-enhancing filters in ski sports, comparisons of injury rates for a variety of sports and venues, the use of computer simulation of knee injuries, and an assessment of how fast winter sports participants travel on the slopes (about 26.
The general framework for our study is signal detection theory (Green & Swets, 1966), which describes the performance of detectors that make binary decisions in a noisy environment in order to determine from which of two overlapping distributions (usually referred to as signal and noise) an event was sampled.
Signal detection theory (SDT) assumes a division of objective truths or "states of the world" into the nonoverlapping categories of signal and noise.
The term K is equivalent to the term known in signal detection theory as [[beta].
For many vigilance researchers, the preferred method of separating the effects of attentional capacity on performance from the effects of an operator's attitudes or performance strategy is to compute the sensitivity (d') and response bias ([Beta]) statistics of signal detection theory (e.
As with the ROC curves, such outcomes further validate the application of signal detection theory in the current study.