Multiple Learner Errors and Meaningful Feedback

This paper describes a web-based ICALL system for German that provides error-specific feedback suited to learner expertise. The main focus of the discussion is on the Domain Knowledge and the Filtering Module. The Domain Knowledge represents the knowledge of linguistic rules and vocabulary, and its goal is to parse sentences and phrases to produce sets of phrase descriptors. Phrase descriptors provide very detailed information on the types of errors and their location in the sentence. The Filtering Module is responsible for processing multiple learner errors. Motivated by pedagogical and linguistic design decisions, the Filtering Module ranks student errors by way of an Error Priority Queue. The Error Priority Queue is flexible: the grammar constraints can be reordered to reflect the desired emphasis of a particular exercise. In addition, a language instructor might choose not to report some errors. The paper concludes with a study that supports the need for a CALL system that addresses multiple errors by considering language teaching pedagogy.