His works like "Principles of Social Education for Deaf and Dumb Children" and "Problems of Mental Retardation" showed his concern for the education of the handicapped, whose difficulties he attributed to social barriers rather than clinical abnormalities.  
His works like "Principles of Social Education for Deaf and Dumb Children" and "Problems of Mental Retardation" showed his concern for the education of the handicapped, whose difficulties he attributed to social barriers rather than clinical abnormalities.  The founder of a laboratory dedicated to the study of defectology, he used the controversial term "pedology" to describe his studies in childhood education.  He is often compared to Piaget because of his theory of cognitive development in children, which argues that the assistance of more experienced peers is crucial to the ability of children to learn concepts outside their limited range of understanding, a process he called "scaffolding." The author of Thought and Language, this is, FTP, what Byelorussian psychologist known for his concept of the zone of proximal development?
His works like "Principles of Social Education for Deaf and Dumb Children" and "Problems of Mental Retardation" showed his concern for the education of the handicapped, whose difficulties he attributed to social barriers rather than clinical abnormalities.  
Lev Vygotsky