Mental rotation and the perspective problem

Experiment I contrasts the difficulty of problems in which a child must anticipate the appearance of an array of objects that is rotated (rotation problems) to the difficulty of problems in which a child must anticipate the appearance of a fixed array to an observer who has been rotated with respect to it (perspective problems). Perspective problems are much more difficult and show a different error pattern. Experiment II contrasts standard perspective problems, in which a child must anticipate the appearance of the array to an observer whose position differs from his own, to “perspective-move” problems, in which a child must anticipate the appearance of the array from his own new position; i.e., he himself moves. The latter problems are much easier, and the error pattern is much like that for rotation problems. The mental operations involved in solving these various types of problems are discussed.