Intelligent Language Tutoring Systems, Learner model, Natural language processing, Online language learning
This commentary reconsiders the description and assessment of the design and implementation of German Tutor, an Intelligent Language Tutoring System (ILTS) for learners of German as a foreign language, published in 2001. Based on our experience over the past 15 years with the design and real classroom use of an ILTS, we address a number of technological and pedagogical issues as they relate to the approach and motivation of designing an ILTS. We also discuss some of the core limitations of German Tutor that eventually resulted in E-Tutor, a modified and enhanced ILTS implemented in 2003 and further expanded in 2009. The commentary concludes with a description of the core contributions of German Tutor as a learner-centered ILTS. Since its initial implementation in 1998, German Tutor has been studied as a component of regular classroom instruction and this body of research has informed not only system upgrades and development but also studies of learner-computer interactions or, computer-assisted language learning (CALL), more generally.