On the basis of their epistemological assumptions alone, both the broad and narrow senses of constructivism offer a psychological parallel to social constructivism. The auxiliary hypotheses of individual constructivist psychologies, such as Piaget’s, may be incompatible with the social constructivist philosophy of mathematics. But the potential for a psychological theory of mathematics learning paralleling social constructivism clearly exists.
A number of researchers are developing a constructivist theory of mathematics learning, including Paul Cobb, Ernst von Glasersfeld and Les Steffe (see, for example, Cobb and Steffe, 1983; Glasersfeld, 1987; Steffe, Glasersfeld, Richards and Cobb, 1983). As they appear to have rejected many of the problematic aspects of Piaget’s work, such as his stages, much of their theory can be seen as parallel to social constructivism, on the psychological plane. However it is not clear that all of their auxiliary assumptions, such as those involved in accounting for young children’s number acquisition, are fully compatible with social constructivism.
No attempt will be made to develop a psychological parallel to social constructivism here, although in the next sections we consider briefly some of the key components of such a theory.
B. Knowledge Growth in Psychology
Following Piaget, schema theorists such as Rumelhart and Norman (1978), Skemp (1979) and others, have accepted the model of knowledge growth utilizing the twin processes of assimilation and accommodation. These offer parallels to the social constructivist accounts of subjective and objective knowledge growth. For knowledge, according to this account, is hypothetico-deductive. Theoretical models or systems are conjectured, and then have their consequences inferred. This can include the applications of know procedures or methods, as well as the elaboration, application, working out of consequences, or interpretation of new facts within a mathematical theory or framework. In subjective terms, this amounts to elaborating and enriching existing theories and structures. In terms of objective knowledge, it consists of reformulating existing knowledge or developing the consequences of accepted axiom systems or other mathematical theories. Overall, this corresponds to the psychological process of assimilation, in which experiences are interpreted in terms of, and incorporated in to existing schema. It also corresponds to Kuhn’s (1970) concept of normal science, in which new knowledge is elaborated within an existing paradigm, which, in the case of mathematics, includes applying known (paradigmatic) procedures or proof methods to new problems, or working out new consequences of an established theory.
The comparison between assimilation, on the psychological plane, and Kuhn’s notion of normal science, in philosophy, depends on the analogy between mental schemas and scientific theories. Both schemas (Skemp, 1971; Resnick and Ford, 1981) and theories (Hempel’ 1952; Quine 1960) can be described as interconnected structures of concepts and propositions, linked by their relationships. This analogy has been pointed out explicitly by Gregory (in Miller, 1983), Salner (1986), Skemp (1979) and Ernest (1990), who analyzes the parallel further.
The comparison may be extended to schema accommodation and revolutionary change in theories. In mathematics, novel developments may exceed the limits of ‘normal’ mathematical theory development, described above. Dramatic new methods can be constructed and applied; new axiom systems or mathematical theories developed, and old theories can be restructured or unified by novel concepts or approaches. Such periods of change can occur at both the subjective and objective knowledge levels. It corresponds directly to the psychological process of accommodation, in which schemas are restructured. It also corresponds to Kuhn’s concept of revolutionary science, when existing theories and paradigms are challenged and replaced.