1986'1, p.64
Shiyanova E. B.
Development of the mental operation of transformation in schoolchildren

The process of development in schoolchildren of mental operations underlying the process of transformation of algebraical expressions has been studied under conditions of experimental teaching. A programme produced for this aim comprized theoretical information on general principles of the algebraical transformation and a system of didactical tasks included in order to organize the process of learning those principles. It has been possible as a result to increase the generality, flexibility, and reflectedness of corresponding mental operations, to promote higher independence of thinking, to stimulate self-control and interest in the subject. At the same time stable individual differences between the children have been observed along a wide range of the experimental material. Some explanations of the phenomenon are provided.