In this paper I shall argue that FEEDBACK constitutes a central but unjustly neglected concept in the study of institutionalized foreign language learning. Since feedback is the crucial element in distinguishing cybernetic from linear models in general, I shall also be adopting the position that language learning, and foreign-language learning in particular, is best represented in cybernetic terms. To date, however, as Crothers and Suppes (1967:19) point out, feedback in psychological literature (and the same is true, I think, for the literature on foreign-language teaching) has usually been characterized simply as a 0, 1 event-that is, as a binary opposition which could be represented as “yes/no.” Our discussion will show, however, that even in the limited communication situation of the foreign-language classroom the students can and do extract much more from the behavior of the teacher than we might suppose – even if what they learn is somewhat different in nature from what the teacher intends. In proposing an explicitly cybernetic approach as a basis for modeling foreign-language learning, we must be careful to point out that this approach has most in common with many models put forward to explain particular processes within biology and, in the study of speech, with those postulated to explain speech degeneration (Arnold 1960, 1961; Gerard 1959; Milisen 1966; West 1957; Wolf and Wolf 1959; Wood 1945) and also some aspects of speech production and perception (Laver's 1970 model is implicitly cybernetic, as are Corder's speculations on the role of error in foreign-language learning. The analysis-by-synthesis model of speech perception, in that it can be reduced to the form HYPOTHESIS + FEEDBACK, is also essentially cybernetic in nature.)