The preceding chapters have discussed the evidence for the probability or improbability of transfer in specific subsystems and specific acquisition contexts. It is now appropriate to consider some of the limitations in transfer research, to review some of the most important tendencies seen in that research, and to discuss some of the areas in which more study of transfer would be useful.

Some caveats

There has been considerable progress in the study of transfer during the last hundred or so years, especially during the years since World War II. Yet the controversies that have accompanied this progress make it clear that the findings of transfer research must be interpreted cautiously. Viewing transfer as the single most important reality of second language acquisition is clearly risky – though no more so than viewing transfer as a negligible factor in acquisition.

In this book there has been relatively little discussion of the individuals studied or of the methods used in the research. A brief look at the studies cited will show considerable variation in the numbers of subjects, in the backgrounds of the subjects, and in the empirical data, which come from tape-recorded samples of speech, from student writing, from various types of tests, and from other sources. Without question, every study has limitations, and virtually every elicitation technique used in the studies has its partisans and its critics (e.g., Tarone 1979; Kohn 1987).