Applied linguistic principles and designing CALL programmes for the ESL classroom

Abstract

Applied Linguistics is largely concerned with teaching English as a second language (TESL) (Cruttenden, 1994, p6). This is not a simple field. There are a number of variables, such as the personalities of the individual students and teachers involved and the approach to learning used. Computer-assisted instruction (CAI) has been used for some years in a variety of approaches and learning environments. In these the primary focus of CAI has been on providing materials for learning in methods that stimulate learning more effectively - either by providing enhanced access to texts or by providing rapid feedback to set problems. The one facet of teaching where CAI is not extensively used (except in a facilitatory role) is providing an environment in which students can practise generating texts and have these understood. This dissertation investigates the potential of using computers to process text in such a way as to enable evaluating the cohesion and coherence of texts. It takes an interdisciplinary approach which exploits methods and insights from applied linguistics, artificial intelligence (AI) and computer-assisted language learning (CALL) to explore the potential of automating textual analysis, comparison and evaluation. This dissertation develops the hypothesis that a dependency-based grammar can be used to generate a computerised representation of the sense contained in a text and that this representation is sufficient to allow contextual comparison of texts. This comparison can be used, in turn, to evaluate texts by means of comparing the representation to that of a model answer, thus providing a means of evaluating the cohesion and coherence of the text. The potential of using such a system in constructing CALL programmes and the extent to which it can assist in the process of second language acquisition (SLA) is also discussed. Existing research studied during the writing of this dissertation included an examination of existing uses of computers in language teaching, particularly those associated with developing communicative competence. These studies pointed to a need for a utility that would enable teaching aids to evaluate texts contextually. Various methods of performing this evaluation were considered. This included the examination of a selection of grammatical systems with a view to determining their strengths in building a representation of the sense contained in a text. In addition, current applications using natural language processing (NLP) and AI were examined with a view to how these could be adapted or used to enable CALL programmes to evaluate coher~nce and cohesion in texts. Furthermore, guidelines are proposed for developing CALL programmes using this type of evaluation. These requirements are used as a template for implementing a programme aimed at performing a contextual evaluation by means of a comparison of texts. This programme is discussed in terms of the grammatical model used as well as the implications this holds for future development. Lastly, the implications using this kind of system in CALL programmes would have for teaching and teacher training are examined and suggestions for the future improvement and development of this sort of application are made. The main conclusion of this dissertation is that computerised contextual evaluation of texts is possible, though with the caveat that the evaluation is limited by the extent to which world-knowledge can be represented.