An experimental test of Piaget's notions concerning the conservation of quantity in children.
D000367:Age Factors; D000704:Analysis of Variance; D002648:Child; D002657:Child Development; D003071:Cognition; D006801:Humans; D007360:Intelligence; D008128:Logic; D011581:Psychological Tests; D012858:Size Perception; D014705:Verbal Behavior