Instruction on Piagetian concepts for children with mental retardation.

Eighteen children with mild mental retardation were pretested on unidimensional classification (oddity), unidimensional seriation, number conservation, Slosson's Intelligence Test, and the Peabody Picture Vocabulary Test (PPVT). The children were instructed on the Piagetian concepts twice per week for 4 months via a learning-set technique. All 315 problems (except 20 verbal classification and 15 verbal seriation items) involved concrete items. When posttested at the semester's end, the children had, with few exceptions, mastered the Piagetian concepts and made significant gains on performance on the PPVT.