W. T. Powers, R. K. Clark, and R. L. McFarland, "A General Feedback Theory of Human Behavior: Part I," Perceptual and Motor Skills 11, 1960


It seems possible that the error tendencies observed in Exp. I can be attrtibuted to the anchoring effect of the card edges on the perception of the positions of points on the cards. If such is the case, then providing further marks on either the stimulus card or the response card or both should influence the error pattern.