Along with the development of systems for natural language understanding and generation, dialog systems have been widely adopted for language learning and practicing. Many current educational dialog systems perform chitchat, where the generated content and vocabulary are not constrained. However, for learners in a school setting, practice through dialog is more effective if it aligns with students' curriculum and focuses on textbook vocabulary. Therefore, we adapt lexically constrained decoding to a dialog system, which urges the dialog system to include curriculum-aligned words and phrases in its generated utterances. We adopt a generative dialog system, BlenderBot3, as our backbone model and evaluate our curriculum-based dialog system with middle school students learning English as their second language. The constrained words and phrases are derived from their textbooks, suggested by their English teachers. The evaluation result demonstrates that the dialog system with curriculum infusion improves students' understanding of target words and increases their interest in practicing English.

翻译：随着自然语言理解与生成系统的发展，对话系统已广泛用于语言学习和练习。当前许多教育对话系统执行自由闲聊，其生成内容和词汇不受约束。然而，对于学校环境中的学习者而言，若对话练习与学生的课程内容保持一致并聚焦于教材词汇，则更具成效。为此，我们将词汇受限解码技术适配至对话系统，以促使对话系统在生成话语中融入课程匹配的词汇和短语。我们采用生成式对话系统BlenderBot3作为基础模型，并以中学生（英语为第二语言）为对象评估基于课程的对话系统。受限词汇和短语源自其教材，并由英语教师建议提供。评估结果表明，融合课程的对话系统能提升学生对目标词汇的理解，并增强其练习英语的兴趣。