Prototypes thus elicited do not, of course, invalidate the observed data of corpus linguistics. They provide a different kind of data which are evidence of competence which is not directly projected into performance. Intuitive, elicited, and observed data all have their own validity, but this validity depends on what kind of evidence you are looking for, on what aspects of language knowledge or behaviour you are seeking to explain. If you are looking for evidence of the internal relationship between language and the mind, you are more likely to favour intuition and elicitation. If you are looking for evidence of how language sets up external links with society, then you are more likely to look to the observed data of actual occurrence. The validity of different kinds of linguistic data is not absolute but relative: one kind is no more 'real' than another. It depends on what you claim the data are evidence of, and what you are trying to explain.
The relevance of linguistics
From questions of validity we turn now to questions of utility. What is linguistics for? What good is it to anybody? What practical uses can it be put to? One response to such questions is, of course, to deny the presupposition that it needs any practical justification at all. Like other disciplines, linguistics is an intellectual enquiry, a quest for explanation, and that is sufficient justification in itself. Understanding does not have to be accountable to practical utility, particularly when it concerns the nature of language, which, as was indicated in Chapter i, is so essential and distinctive a feature of the human species.
Whether or not linguistics should be accountable, it has been turned to practical account. Indeed, one important impetus for the development of linguistics in the first part of this century was the dedicated work done in translating the Bible into languages hitherto unwritten and undescribed. This practical task implied a prior exercise in descriptive linguistics, since it involved the analysis of the languages (through elicitation and observation) into which the scriptures were to be rendered. And this necessarily called for a continual reconsideration of established linguistic categories to ensure that they were relevant to languages other than those, like English, upon which they were originally based. The practical tasks of description and translation inevitably raised issues of wider theoretical import.
They raise other issues as well about the relationship between theory and practice and the role of the linguist, issues which are of current relevance in other areas of enquiry, and which bear upon the relationship between descriptive and applied linguistics.
The process of translation involves the interpretation of a text encoded in one language and the rendering of it into another text which, though necessarily different in form, is, as far as possible, equivalent in meaning. In so far as it raises questions about the differences between language codes it can be seen as an exercise in contrastive analysis. In so far as it raises questions about the meaning of particular texts, particular communicative uses of the codes, it can be seen as an exercise in discourse analysis. Both of these areas of enquiry have laid claim to practical relevance and so to be the business of applied linguistics.
With regard to contrastive analysis, one obvious area of application is language teaching. After all, second language learning, like translation, has to do with working out relationships between one language and another: the first language (L1) you know and the second language (L2) you do not. It seems self-evident that the points of difference between the two codes will constitute areas of difficulty for learners and that a contrastive analysis will therefore be of service in the design of a teaching programme.
It turns out, however, that the findings of such analysis cannot be directly applied in this way. Although learners do undoubtedly refer the second language they are learning (L2) to their own mother tongue (L1), in effect using translation as a strategy for learning, they do not do so in any regular or predictable manner. Linguistic difference is not a reliable measure of learning difficulty. The data of actual learner performance, as established by error analysis, call for an alternative theoretical explanation.
One possibility is that learners conform to a pre-programmed cognitive agenda and so acquire features of language in a particular order of acquisition. In this way they proceed through different interim stages of an interlanguage which is unique to the acquisition process itself. Enquiry into this possibility in Second Language Acquisition (SLA) research has been extensive.
There is another possibility. It might be that the categories of description typically used in contrastive analysis are not sufficiently sensitive to record certain aspects of learner language. Learners may be influenced by features of their L1 experience other than the most obvious forms of the code. Contrastive analysis has been mainly concerned with syntactic structure, but this is only one aspect of language, and one which, furthermore, inter-relates with others in complex ways. So it may be that the learners' difficulties do correspond to differences between their L1 and L2, but that we need a more sophisticated theory to discern what the differences are, a theory which takes a more comprehensive view of the nature of language by taking discourse into account.
Discourse analysis is potentially relevant to the problems of language pedagogy in two other ways. Firstly, it can provide a means of describing the eventual goal of learning, the ability to communicate, and so to cope with the conventions of use associated with certain discourses, written or spoken. Secondly, it can provide the means of describing the contexts which are set up in classrooms to induce the process of learning. In this case it can provide a basis for classroom research.
But the relevance of discourse analysis is not confined to language teaching. It can be used to investigate how language is used to sustain social institutions and manipulate opinion; how it is used in the expression of ideology and the exercise of power. Such investigations in critical discourse analysis seek to raise awareness of the social significance and the political implications of language use. Discourse analysis can also be directed to developing awareness of the significance of linguistic features in the interpretation of literary texts, the particular concern of stylistics.
In these and other cases, descriptive linguistics becomes applied linguistics to the extent that the descriptions can be shown to be relevant to an understanding of practical concerns associated with language use and learning. These concerns may take the form of quite specific problems: how to design a literacy programme, for example, or how to interpret linguistic evidence in a court of law (the concern of the growing field of forensic linguistics).
But other concerns for relevance are more general and more broadly educational. We began this book by noting how thoroughly language pervades our reality, how central it is to our lives as individuals and social beings. To remain unaware of it what it is and how it works is to run the risk of being deprived or exploited. Control of language is, to a considerable degree, control of power. Language is too important a human resource for its understanding to be kept confined to linguists. Language is so implicated in human life that we need to be as fully aware of it as possible, for otherwise we remain in ignorance of what constitutes our essential humanity.