APA Dictionary of Psychology

a test used to study the role of visual and gravitational cues in judging the visual vertical. It is the most widely used measure of visual field dependence and field independence. The test consists of a movable rod inside a frame; the participant must adjust the rod to a true vertical position as the position of the frame is changed. Degree of error (i.e., the number of degrees away from 90°) is the measure used to score the test. The higher the score, the more field dependent the participant is; the lower the score, the more field independent they are. [developed in 1948 by U.S. psychologists Herman A. Witkin (1916–1979) and Solomon Asch]