Applied linguistic principles and designing CALL programmes for the ESL classroom

[摘要] 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 numberof variables, such as the personalities of the individual students and teachers involvedand the approach to learning used. Computer-assisted instruction (CAI) has been usedfor some years in a variety of approaches and learning environments. In these theprimary focus of CAI has been on providing materials for learning in methods thatstimulate learning more effectively - either by providing enhanced access to texts orby providing rapid feedback to set problems. The one facet of teaching where CAIis not extensively used (except in a facilitatory role) is providing an environment inwhich students can practise generating texts and have these understood.This dissertation investigates the potential of using computers to process text insuch a way as to enable evaluating the cohesion and coherence of texts. It takes an interdisciplinaryapproach which exploits methods and insights from applied linguistics,artificial intelligence (AI) and computer-assisted language learning (CALL) to explorethe potential of automating textual analysis, comparison and evaluation.This dissertation develops the hypothesis that a dependency-based grammar canbe used to generate a computerised representation of the sense contained in a textand that this representation is sufficient to allow contextual comparison of texts. Thiscomparison can be used, in turn, to evaluate texts by means of comparing the representationto that of a model answer, thus providing a means of evaluating the cohesionand coherence of the text. The potential of using such a system in constructing CALLprogrammes and the extent to which it can assist in the process of second languageacquisition (SLA) is also discussed.Existing research studied during the writing of this dissertation included an examinationof existing uses of computers in language teaching, particularly those associatedwith developing communicative competence. These studies pointed to a need for a utilitythat would enable teaching aids to evaluate texts contextually. Various methods ofperforming this evaluation were considered. This included the examination of a selectionof grammatical systems with a view to determining their strengths in building arepresentation of the sense contained in a text. In addition, current applications usingnatural language processing (NLP) and AI were examined with a view to how thesecould be adapted or used to enable CALL programmes to evaluate coher~nce and cohesionin texts. Furthermore, guidelines are proposed for developing CALL programmesusing this type of evaluation.These requirements are used as a template for implementing a programme aimedat performing a contextual evaluation by means of a comparison of texts. This programmeis discussed in terms of the grammatical model used as well as the implicationsthis holds for future development.Lastly, the implications using this kind of system in CALL programmes wouldhave for teaching and teacher training are examined and suggestions for the futureimprovement and development of this sort of application are made.The main conclusion of this dissertation is that computerised contextual evaluationof texts is possible, though with the caveat that the evaluation is limited by the extentto which world-knowledge can be represented.

[发布机构] University of the Free State