title: Classification training in two- and three-year-old children.
mesh_terms: D000367:Age Factors; D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D003118:Color Perception; D003210:Concept Formation; D004193:Discrimination Learning; D005260:Female; D005556:Form Perception; D006801:Humans; D007100:Imitative Behavior; D008297:Male; D011582:Psychological Theory; D012054:Reinforcement, Psychology; D012858:Size Perception