Evidence suggests that the speech behavior of language learners may be structurally organized and that the contact situation should therefore be described not only by reference to the source (SL) and target (TL) languages of the learner, but also by reference to a learner system (AL). Investigation of such learner systems is crucial to the development of contrastive analysis theory and to its application to language teaching. However, these systems also merit investigation in their own right through their implications for general linguistic theory. Experimental and informal observation of the contrastive approach in its present form reveal serious limitations, in part because learner behavior cannot be exhaustively described without reference to the AL. Theoretical and practical considerations therefore converge to suggest the direct and systematic examination of such learner speech, viewed within the general framework of the current theory. Such investigation would (1) provide attested information, of immediate utility in teaching and course development, on patterns of learning behavior for the principal structures of the target languages; (2) permit further assessment of the current suppositions of contrastive analysis; and (3) make possible a preliminary description of AL, thus progressing toward a reformulated contrastive approach. (Author/DO)