PromisD: ein Analyseverfahren zur antizipationsfreien Erkennung und Erklärung von grammatischen Fehlern in Sprachlernsystemen

The dissertation starts with an analysis of the requirements for Intelligent Computer-Assisted Language Learning systems (ICALL), which partially depend on didactic aspects of foreign language teaching. Based on this a type of exercise can be identified, that on the one hand allows the learner to enter free formed input supporting the so called communicative competence as a major didactic goal and on the other hand may be realised with advanced computational linguistics’ methods. In the following chapter a look at grammar theories and especially Lexical Functional Grammar (LFG) is taken. The grammar theory needs to be tractable in an implementation and it is of a further advantage if the concepts of the theory are similar to the concepts in learner grammars in order to simplify the generation of feedback. Subsequently the user interface of the actual program is presented with a focus on error messages. The implementation is named PromisD, which stands for ‘Projekt mediengestütztes interaktives Sprachenlernen Deutsch’. Finally an anticipation-free parsing method is developed using neither information from the lexicon nor the grammar in order to identify grammar errors. The recognition is restricted to those areas where errors occur frequently in a learner corpus in order to allow for a greater efficiency parsing authentic data. Along the two structural levels in LFG the presentation of the algorithm follows: the constituent-structure with a modified Early-algorithm integrating error hypotheses into the chart and the featurestructure with a new unification-strategie storing information about clashing values in the f-structure. The dissertation closes with an evaluation and an outlook on the generation of error messages.