Various counting tasks were presented to 24 congenitally, totally blind children, aged 3-13, to determine the behaviors employed to ensure accurate counting. Three dimensions of tactile strategies were found, including "scanning,""organizing," and "partitioning." A developmental progression in the ontogenesis of each…

Two studies on cognitive performance in mentally retarded children are reported. In the first study, the Bayley Scales of Infant Development were administered to 56 mentally retarded children, aged 2 to 6, to determine the possibility of discerning subsets of items that form a developmental pattern of interrelated subscales, using the SCAMMO scale…