CONCEPT FORMATION: THE FEATURE-POSITIVE EFFECT (Cat. #815)

Donald E. Mintz, Ph.D

The feature-positive effect is a very robust phenomenon. In concept formation the "feature", the stimulus element that defines the concept, may be present (feature-positive) or absent (feature-negative). In this demonstration, two series of trials are provided with identical pairs of stimuli. Students must decide which is the "correct" choice, with immediate feedback given. When the feature is positive, the vast majority of students will learn the concept in the 30 trials provided. When the feature is negative, it is a near certainty that the concept will not be learned. The program provides a useful basis for introducing concept-formation and for demonstrating the not-well-known feature-positive effect. Cumulative data are recorded.

Unknown to the subject this is the Feature Positive condition and the correct feature is "green", therefore, selecting "1" is the correct choice. Subjects soon learn the correct response in the Feature Positive condition. In the Feature Negative condition, "2" would be the correct choice because the feature "green" is absent. Under this condition few subjects learn the correct choice.