THE TEACHER MODE OF THE SENTENCE FAIRY SYSTEM: HOW TO CREATE YOUR OWN E-LEARNING WRITING LESSONS FOR GERMAN ELEMENTARY SCHOOL PUPILS
Karin Harbusch, Christian Franz, Ulrich Koch · 2012
The Sentence Fairy system implements a “virtual writing conference ” for elementary-school children, with German as the target language. It deploys natural-language generation technology to evaluate and improve the grammatical quality of learner output. Based on an abstract representation of the story under construction, all paraphrases of simple and combined clauses are generated fully automatically. From this source, the system produces exercises enabling the learners to improve their sentences. So far, the abstract story representations had to be written by skilled linguists. Through the new teacher mode, users with elementary linguistic knowledge about constituents of simple clauses can enter their own story, which is then automatically translated into e-learning exercises. The teachers are supposed to fill constituents of simple clauses into a drop-down menu, with the system adding grammatical functions such as Subject, Direct Object, Modifier, etc. This way of specifying a sentence prevents syntactic ambiguity, thereby promoting the accuracy of feedback generation by the system. The information on rhetorical relations such as causality and temporal order, which provide the basis for a variety of sentence combination exercises, is also entered in a dialogue without technical terms. Moreover, the teacher mode allows the specification of lexical-choice alternatives. The system automatically generates a suggestion list for all words of the story by selecting synonyms, hyponyms and hyperonyms in WORDNET.