Children with mild learning difficulties (MLD) who had not developed conservation of number, length, weight, and volume worked on conservation problems. MLD children who worked on the problems with another child who challenged their nonconserving responses made more progress on the problems than did MLD children who worked on the problems in…

Children between 7 and 11 years of age with moderate learning difficulties were tested for conservation. Nonconservers were divided into experimental and control groups. Experimental group children performed conservation tasks with conserving children in their class. Posttests indicated that the increase in performance in conservation tasks was…

Studies the sequence in development of conservation concepts in 19 language-impaired children aged 6-9 years and 20 children of 3-11 years who had no impairment. The two groups showed a similar sequence of development regardless of delay. Conservation of number appeared first, followed by weight, substance, length, area, and volume. (RJC)

Investigated the cognitive development of children with emotional and behavioral difficulties (EBDs). Found that children with EBDs showed a similar order of acquisition of conservation as normal children, and the thinking of children with EBDs was characterized by a high degree of uncertainty. (BC)

Describes an exploratory investigation of blind children's concepts of number, substance, length, area, weight, and volume conservation. Six children totally without sight or with only light perception were pretested, taught, and posttested twice using tasks specifically adapted for tactual presentation of materials. The children showed increased…

Investigates the development of understanding of quantity in 36 children with Down's Syndrome. Findings confirmed similarities in sequence of development between Down's Syndrome children and nonretarded children. Down's children who received training recognized conservation of continuous and discontinuous quantity. (RJC)

Nonretarded (NR) and educable mentally retarded (EMR) 6- to 19-year-old children in Istanbul, Turkey, completed conservation tasks. Found a similarity in the developmental progression of conservation concepts between the two groups and between these groups and groups of NR and EMR children in England as reported in previous studies. (BC)

Investigates the extent of similarity in the sequence of development of concepts in children with Down's Syndrome, children with other forms of retardation, and nonretarded children. (Author/BB)

Through seriation, verbal seriation, and conservation tasks, investigated blind, partially sighted, and sighted children's understanding of quantity. Subjects were 81 children equally dispersed through these 3 groups. Age range was 4 to 17 years. Found similarity in concept acquisition among three groups that extended beyond quantity conservation…