Developing and maintaining constructive engagement is a crucial challenge in learning by watching videos. AVW-Space is an online video-based learning platform which enhances student engagement via note-taking and personalised support. Previous studies with AVW-Space show that students who write comments, especially high-quality comments, learn more. The goal of the study reported in this paper is to encourage students to write better-quality comments. After automating the assessment of comment quality using machine learning approaches, we developed Quality nudges which encourage students to write better comments. We conducted a study in a first-year engineering course to analyse the learning effects of the Quality nudges. The results show that Quality nudges enhanced constructive engagement and learning. The contribution of this research is in proposing methodology for increasing the quality of student comments in video-based learning.

发展和保持建设性的参与是通过观看视频学习的一个关键挑战。AVW-Space 是一个基于在线视频的学习平台，它通过记笔记和个性化支持来提高学生的参与度。以前使用 AVW-Space 进行的研究表明，写评论的学生，尤其是高质量的评论，会学到更多。本文报告的研究目标是鼓励学生写出更好质量的评论。在使用机器学习方法自动评估评论质量后，我们开发了质量助推器，鼓励学生写出更好的评论。我们在第一年的工程课程中进行了一项研究，以分析质量助推的学习效果。结果表明，质量推动增强了建设性的参与和学习。