We have developed a new CALL system to aid students learning Japanese as a second language. The system offers students the chance to practice the Japanese grammar and vocabulary, by creating their own sentences based on visual prompts, before receiving feedback on their mistakes. Questions are dynamically generated along with sentence patterns of the lesson point, to realize variety and flexibility of the lesson. Students can give their answers with either text input or speech input. To enhance speech recognition performance, a decision tree-based method is incorporated to predict possible errors made by non-native speakers for each generated sentence on the fly. Trials of the system have been conducted with a number of foreign students in our university, and positive feedbacks were obtained.
Bibliographic reference. Wang, Hongcui / Kawahara, Tatsuya (2008): "A Japanese CALL system based on dynamic question generation and error prediction for ASR", In INTERSPEECH-2008, 1737-1740.