The Phantom Plateau Returns

Abstract

The question of whether learning curves of such cognitive-motor skills as typing and telegraphic transmission typically show plateaus where presumably subskills are being consolidated has been a matter of controversy. Reinforcement theorists argue that learning occurs steadily if equal amounts of reinforcement are applied to equal amounts of material. However, feedback control theory suggests that a complex skill involves a hierarchy of perceptual variables each level comprising the components of the next level. Plateaus should be expected where a subject must master a task one level at a time. 30 subjects were tested on a computerized “game” containing a three-level hierarchical task. Not all subjects showed plateaus. Verbalizations of the subjects during the task suggested that a crucial difference was in whether the subject worked systematically on one level before attending to the next variable. Among subjects who achieved genuine solutions mathematics and physics students used fewer trials than anthropology and psychology students. Anecdotal evidence suggested that they used hypothesis-testing strategies more frequently. It was also noted that the task might be construed differently by different subjects so they are not necessarily doing the same thing even when perceived as performing the same task by the experimenter.