Development of a VOD lecture learning system that matches the Japanese comprehension levels of foreign students

由于过去的许多VOD讲座只是用视觉图像和PowerPoint展示的材料，外国学生很难使用它们。在开发符合外国学生日语理解水平的VOD讲座学习系统时，除了增加字幕和提供简单字幕外，我们还开发了中文搜索功能和自主学习主题搜索功能。此外，我们还对日语单词的难易程度进行了评估，并从词典和网络中进行了数据采集；通过改进机器学习技术，我们开发了一个系统，可以从所用单词的难度程度来评估实际VOD讲座的难度程度。

Since many VOD lectures in the past were only materials displayed with visual images and in PowerPoint, it was difficult for foreign students to use them as they were. In the development of a VOD lecture learning system that matches the Japanese comprehension levels of foreign students, besides adding subtitles and providing simple subtitles, we developed a Chinese search function and a search function for self-learning topics. Furthermore, we assessed the difficulty of Japanese words with unclear levels of difficulty and carried out data acquisition from dictionaries and the Web; by improving the machine learning technique, we developed a system that evaluates the level of difficulty of the actual VOD lecture from the level of difficulty of the words used.