Research into learners’ ideas about science suggests that students often have alternative conceptions about important science concepts. Because of this dissatisfaction, constructivism has been adopted as a theoretical framework by many teachers and researchers, and it has had a curricular influence in many countries. Constructivism is much more than an educational doctrine and we are aware that a ‘science war’ about the possibility of objectivity is in progress. ‘Constructivism’ cannot necessary be a package deal: it must be possible to accept educational suggestions deemed useful without buying all the epistemology or the metaphysical implications. The claim that cognitive agents understand the world by constructing mental representations of it can be a shared suggestion for changing science instruction. Many teachers are much more concerned in finding productive teaching methods than about philosophical questions as if knowledge must be considered an objective representation of the real world or not. We have to ponder if some ideas from the constructivist theory of instruction can help instructors to become better teachers. The pragmatic suggestions that come from the constructivist theory of instruction developed by von Glasersfeld, the leading proponent of radical constructivism, could be a good start in this search.

Key words: Ernst von Glasersfeld, forms of constructivism, objectivity, constructivist theory of instruction.

Constructivism rejects the metaphysical position that “truth,” and thus knowledge in science, can represent an “objective” reality, independent of the knower. It modifies the role of knowledge from “true” representation to functional viability. In this interview, Ernst von Glasersfeld, the leading proponent of Radical Constructivism underlines the inaccessibility of reality, and proposes his view that the function of cognition is adaptive, in the biological sense: the adaptation is the result of the elimination of all that is not adapted. There is no rational way of knowing anything outside the domain of our experience and we construct our world of experiences. In addition to these philosophical claims, the interviewee provides some personal insights; he also gives some suggestions about better teaching and problem solving. These are the aspects of constructivism that have had a major impact on instruction and have modified the manner many of us teach. The process of teaching as linguistic communication, he says, needs to change in a way to involve actively the students in the construction of their knowledge. Because knowledge is not a transferable commodity, learning is mainly identified with the activity of the construction of personal meaning. This interview also provides glimpses on von Glasersfeld’s life.

Key words: radical constructivism, education

This commentary is a critical appraisal of Gil-Pérez et al. ‘s (2002) conceptualization of constructivism. It is argued that the following aspects of their presentation are problematic: (a) Although the role of controversy is recognized, the authors implicitly subscribe to a Kuhnian perspective of “normal’ science; (b) Authors fail to recognize the importance of von Glasersfeld’s contribution to the understanding of constructivism in science education; (c) The fact that it is not possible to implement a constructivist pedagogy without a constructivist epistemology has been ignored; and (d) Failure to recognize that the metaphor of the “student as a developing scientist’ facilitates teaching strategies as students are confronted with alternative/rival/conflicting ideas. Finally, we have shown that constructivism in science education is going through a process of continual critical appraisals.