Jean William Fritz Piaget (UK: /piˈæʒeɪ/,[1][2] US: /ˌpiːəˈʒeɪ, pjɑːˈʒeɪ/;[3][4][5] French: [ʒɑ̃ pjaʒɛ]; 9 August 1896 – 16 September 1980) was a Swiss psychologist known for his work on child development.

[21] Piaget was familiar with many of Claparède's ideas, including that of the psychological concept of groping which was closely associated with "trials and errors" observed in human mental patterns.

Piaget died on 16 September 1980, and, as he had requested, was buried with his family in an unmarked grave in the Cimetière des Rois (Cemetery of Kings) in Geneva.

[29] The theorist we recognize today only emerged when he moved to Geneva, to work for Édouard Claparède as director of research at the Rousseau Institute, in 1922.

[37] For example, young children in the preoperational stage engage in "irreversible" thought and cannot comprehend that an item that has been transformed in some way may be returned to its original state.

The sensorimotor stage is divided into six substages:[43]Some followers of Piaget's studies of infancy, such as Kenneth Kaye[44] argue that his contribution was as an observer of countless phenomena not previously described, but that he didn't offer explanation of the processes in real time that cause those developments, beyond analogizing them to broad concepts about biological adaptation generally.

During the preoperational stage of cognitive development, Piaget noted that children do not yet understand concrete logic and cannot mentally manipulate information.

By observing sequences of play, Piaget was able to demonstrate that, toward the end of the second year, a qualitatively new kind of psychological functioning occurs, known as the preoperational stage.

A late turn in the development of Piaget's theory saw the emergence of work on the accomplishments of those children within the framework of his psychology of functions and correspondences.

According to Piaget's Genevan colleagues,[50] the "semilogic" of these order functions sustains the preoperational child's ability to use of spatial extent to index and compare quantities.

[46] Piaget (1977) wrote that "correspondences and morphisms are essentially comparisons that do not transform objects to be compared but that extract common forms from them or analogies between them" (p. 351).

Each new stage emerges only because the child can take for granted the achievements of its predecessors, and yet there are still more sophisticated forms of knowledge and action that are capable of being developed.

A schema (plural form: schemata) is a structured cluster of concepts, it can be used to represent objects, scenarios or sequences of events or relations.

He could not find the path of logic reasoning and the unspoken thoughts children had, which would allow him to study a child's intellectual development over time (Mayer, 2005).

In his third book, The Child's Conception of the World, Piaget recognized the difficulties of his prior techniques and the importance of psychiatric clinical examination.

Developmental psychologists today do not view development as taking place in stages[60][61] and many of Piaget's empirical findings have been overturned by subsequent research.

They recognize his innovative empirical work, his attempts to integrate his results into a unified theoretical model and the way he created a path for subsequent researchers to follow.

It allows teachers to view students as individual learners who add new concepts to prior knowledge to construct, or build, understanding for themselves.

[69] In an older child at the concrete operational level, decentration allows him to complete subtraction of two-digit numbers and indicate which of the problems also involved borrowing from the other column.

[71] Evidence of the effectiveness of a contemporary curricular design building on Piaget's theories of developmental progression and the support of maturing mental structures can be seen in Griffin and Case's "Number Worlds" curriculum.

The cognitive scientist Karen Fuson has argued that the impact of Piagetian theories in education has not been entirely positive because his work has frequently been misinterpreted.

Under these conditions, authentic forms of intellectual exchange become possible; each partner has the freedom to project his or her own thoughts, consider the positions of others, and defend his or her own point of view.

In such circumstances, where children's thinking is not limited by a dominant influence, Piaget believed "the reconstruction of knowledge", or favorable conditions for the emergence of constructive solutions to problems, exists.

For example, the philosopher and social theorist Jürgen Habermas has incorporated Piaget into his work, most notably in The Theory of Communicative Action.

The philosopher Thomas Kuhn credited Piaget's work with helping him to understand the transition between modes of thought which characterized his theory of paradigm shifts.

[87] Shortly before his death (September 1980), Piaget was involved in a debate about the relationships between innate and acquired features of language, at the Centre Royaumont pour une Science de l'Homme, where he discussed his point of view with the linguist Noam Chomsky as well as Hilary Putnam and Stephen Toulmin.

Other shortcomings of Piaget’s theory include overestimating an adolescent's cognitive abilities, underestimating an infant’s, and overlooking how much cultural and social factors affect children’s thinking.. As Piaget worked in the era before widespread use of voice recording equipment, his data collection method was simply to make handwritten notes in the field, which he would analyse himself.

[89] These methodological issues mean scientists trying to replicate Piaget's experiments have found that small changes to his procedures lead to different results.

Modern cognitive science had undermined Piaget's view that young children are unable to comprehend numbers as they are not able to work with abstract concepts in the sensorimotor stage.

This Piagetian view has led many educators to believe that it is not appropriate to teach simple arithmetic to young children as it will not lead to real understanding.