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commodity theory

a theory proposing that the value of a product or service is related to its availability. In general, a product that is in short supply is perceived as having greater value than one that is readily available. However, a product’s value is also related to the demand for it. It may be scarce, but if no one wants it, it will not have a high value. Commodity theory is used to explain consumer behavior in times of product or service restriction. [formulated in 1968 by Timothy C. Brock]

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Psychology term of the day

May 10th 2024

guilty knowledge test

guilty knowledge test

a form of lie detection in which knowledge about the details of a crime is tested. A polygraph examiner presents examinees with multiple-choice questions concerning the crime, to which only the guilty party should know the correct answers; it is assumed that innocent examinees will see all options as equally plausible. The polygraph examiner measures the examinees’ physiological arousal as each option is presented and identifies which option produces the highest physiological response. Over a series of questions, if an individual consistently shows the greatest response to the correct option, the examiner may identify that person as untruthful in his or her denial of knowledge of the details of the crime. See also control question test; relevant–irrelevant test.