1. a systematic procedure for comparing a set of stimuli or other items. A pair of stimuli is presented to an individual, who is asked to compare them on a particular dimension, such as size, loudness, or brightness; the process is continued until every item in the set has been compared with every other item. The method is mainly associated with research into psychophysical judgments but has also been used to study preferences between works of art or different personality characteristics.

2. in industrial and occupational settings, a method of employee evaluation in which each worker in a selected group is compared with every other worker on a series of performance measures. Employees are then rated on the basis of the number of favorable comparisons they receive.