Radical constructivism is an approach to epistemology that situates knowledge in terms of knowers' experience.
[2][5] Radical constructivism was initially formulated by Ernst von Glasersfeld, who drew on the work of Jean Piaget, Giambattista Vico, and George Berkeley amongst others.
[6][7] Radical constructivism is closely related to second-order cybernetics,[8] and especially the work of Heinz von Foerster, Humberto Maturana, and Francisco Varela.
During the 1980s, Siegfried J. Schmidt played a leading role in establishing radical constructivism as a paradigm within the German speaking academic world.
[13] Constructivist Foundations is a free online journal publishing peer-reviewed articles on radical constructivism by researchers from multiple domains.