ALBERT

Notes: Conclusions The main feature of Piaget & Garcia's study (1989) is the overture of a new field of research within the Piagetian framework, namely the comparative study of individual and historical development. During the 80's, several alternative models have been offered to account for the relations between individual and historical development. However, it has been suggested that ‘there [...] appears to be widespread agreement among Piagetians and non-Piagetians that common mechanisms and processes underlie the thinking of scientists and children at all times’ (Gauld 1990, p. 24–5). The development of this field of research demands that theoretical research be conducted regarding the possible patterns of relationship between individual and historical development, that should be integrated to comparative empirical research on diverse topics. Further studies would then be required to provide an empirical basis for the comparative research. In other words, this field of research demands the close collaboration between epistemologists, historians, science educators, and cognitive psychologists. We have suggested that the Piagetian model needs to provide a more convincing account of the differences between individual and historical development, and of the role of internal and external factors in the progress of science. We have also argued for an overcoming of the overemphasized structural aspects of the theory, and for an unambiguous concept of history. The non-Piagetian approaches have their own strength and may be developed as alternatives to the Piagetian model. However, our intention here is to emphasize their potential contribution to the development of Piaget's theory. In McCloskey and Kargon (1988) we may find hints to deal with the specificity of similarities in content. Nersessian (1987) provided an excellent insight on how to deal with Kuhn's concept of incommensurability. 5 In our interpretation, Carey's work suggest that considering the relation between content and development of structures may be a productive way of developing Piaget's theory. Finally, we would like to comment on the relationship between Piaget's theory and research on students' thinking in science. Both adopt a constructivist stance. However, the vast majority of researchers have developed a strong resistance to Piaget's theory (e.g. Novak 1978; Gilbert and Swift 1985). On the one hand, this resistance should be considered a natural and healthy tendency toward a pluralistic development of research in science education. On the other hand, it may be a consequence of the difficulty of Piaget's theory in coping with the main research findings on spontaneous reasoning. In short, while many researchers in science education have emphasized the persistence of children's, adolescents' and adults' alternative conceptions, Piaget's theory suggests that reaching the formal stage is a necessary condition to understand science. This contradiction will not be overcome while Piagetian researchers are not able to offer a better account of the differences between commonsense knowledge and scientific knowledge. Freed from the constraints of the Piagetian approach, research on alternative conceptions showed an amazing development during the late 70's and the 80's. 6,7 Further progress, however, increasingly requires theoretical tools to manage the great amount of data already available, and models to explain, rather than just describe, individuals' thought. This task can be carried out from within different theoretical approaches. In Psychogenesis and the History of Science, Piaget and Garcia presented an updated and strong model for the relationship between individual and historical development. If used in an open-minded way, this model may contribute to the development of research in science education.