progress it stimulated in formal linguistics, should be recognized as an extremely important contribution, and easily outdid previous theories of linguistic structure. My point here is that it does not necessarily follow that second language methods and materials should be based directly on TG.)

These two theories, then, failed. The first, behaviorist theory, failed to apply successfully to language teaching because it was, simply, not a theory of language acquisition. The second, TG, failed because it was a theory of the product, the adult's competence, and not a theory of how the adult got that competence. It is not a theory of the process of language acquisition.

The "new" theory, which I will present in Chapter II, is a theory of second language acquisition, and attempts to deal with the process of language acquisition, not its product. Despite these virtues, it should only be considered one of several possible sources of information in determining methods and materials for second language teaching.

Compounding the failure of theoreticians to supply relevant theory has been the feeling among practitioners that failure to make the theory "work" has been their fault. They incorrectly concluded that it was their ignorance of theory that caused these theory-based methods to fail. As a result of this, teachers in recent years have appealed mostly to area III, their own ideas and intuitions, in determining what they do in the classroom. What teachers actually do is no longer based on theoretical or applied research. Materials, and many books on methodology, are based primarily on what seems to work in the classroom, and only rarely on a theory (recall earlier books based on audiolingualism or TG), and are usually not field-tested.

C. What the Three Approaches Have to Say About Method

The purpose of this book is to summarize one current theory and state the implications of the theory to method. I will briefly summarize here what some of these implications are, anticipating Chapter III. What current theory implies, quite simply, is that language acquisition, first or second, occurs only when comprehension of real messages occurs, and when the acquirer is not "on the defensive", to use Stevick's apt phrase. Language acquisition does not require extensive

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