The second-order cybernetics worked out by Heinz von Foerster is rightly held to be a constructivist theory, if no an a manifesto for operational constructivism. The reverse doesn't apply, however. Constructivist epistemologies do not necessarily have the rigor of a cybernetics of cybernetics. One can obeserve congnitions as constructions of an observer, without linking with this the theory that the observing observer observes himself or herself as an observer.

p. 117 - The reality of the Mass Media (2000)