A test of Piaget's explanation of the Müller-Lyer illusion.
D003071:Cognition; D004215:Distance Perception; D005556:Form Perception; D049673:History, 20th Century; D006801:Humans; D007088:Illusions; D007257:Information Theory; D007600:Judgment; D009949:Orientation; D011582:Psychological Theory; D011584:Psychology / Q000266:history; D013028:Space Perception; D014796:Visual Perception