Performance of retarded children on a liquid conservation task: protocol objectivity and visual screening.
D000293:Adolescent; D002648:Child; D002657:Child Development; D003071:Cognition; D003210:Concept Formation; D005260:Female; D006801:Humans; D008607:Intellectual Disability; D007360:Intelligence; D008297:Male; D013647:Task Performance and Analysis; D014796:Visual Perception