title: Variations in children's concepts by age and category.
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007804:Language Development; D008297:Male; D011939:Mental Recall; D012153:Retention, Psychology; D012660:Semantics; D014706:Verbal Learning; D014825:Vocabulary