her hand, is embedding naturally, i.e. it is a subconscious process which encodes subconscious forms and processes, viz. knowledge. "In everyday language, acquisition is 'picking up' language, while learning is 'grammar' or 'rules'" (Krashen 35). Whether one is a proponent of Krashen's psycholinguistic theories or not is of relatively little consequence in the matter of instruction's effects on language learning and/or acquisition--"naturalists" non obstante. It remains that the epistemic approach responds to the logical and empirical concerns of ESL teachers: It is a pragmatic and sensible approach to the development of ESL didactic methodologies. Moreover, it is a sound operational basis on which to ascertain the effects of instruction on linguistic processes--if any. The error, however, would be to confine one's theoretical foundation to Krashen's psycholinguistics.
It is not difficult to influence the structure, tempo, and termination of the acquisition process. "The obvious way to do this consists in trying to control skillfully the interactive influences of the various factors. It is less clear that the various factors differ in the degree to which they are amenable to this control. The factor easiest to control is access, from the point of view of the input as well as of opportunity to communicate. It is possible, although not quite as easy, to influence the propensity to acquire the target language. Most difficult to control is the language processor itself" (Klein 53). Does this mean that extrinsic factors can be modified through instruction, whereas intrinsic factors cannot? Is it that what is taught can be manipulated, whereas who is taught presents a much more arduous task? If environmental output can be readily modified, but acquisition system input is more complex and resistant to inclusion (entry in processing system called "learning/acquisition"), then, isn't instruction an inadequate and possibly even inappropriate s...