Background. In connection with the 80^thanniversary of a famous Russian psychologist, Professor of Developmental Psychology, Faculty of Psychology, Lomonosov Moscow State University, Lyudmila F. Obukhova it is relevant to analyse one of the most striking pages in her scientific heritage associated with her experimental study of the conditions and mechanisms of child thinking development.

The Objective is to consider the experimental model of the child’s transition from one stage of cognitive development to another elaborated by L. F. Obukhova on the basis of Pyotr Ya. Galperin’s theory, and to compare it with two alternative models created by the followers of J. Piaget in the Geneva psychological school (B. Inhelder, M. Bovet, H. Sinclair) and in the framework of American cognitive psychology (R. Siegler).

Design. Comparative analysis of the theoretical foundations and effectiveness of the three approaches to child cognitive development modeling, as well as the adequacy and completeness of the conceptual description of the according three experimental procedures: formative experiment, cognitive learning and microgenetic observation. 

Results. The method of L. F. Obukhova was the first significant attempt to reproduce the process and mechanisms of child’s transition from the preoperational stage of development to the operational stage in the conditions of the forming experiment. Using the method of "cognitive learning" allowed identifying the discrepancy between its actual psychological content and the interpretation of intellectual development as a spontaneous process. The evolution of microgenetic approach up to the modern position is traced through the identity of development and learning. 

Concusion. In contrast to the "cognitive learning" and microgenetic analysis method, the forming model of the study allows  recreating essential conditions of child cognitive development that are usually scattered in the spontaneous experience of the child and stretched in time.