Effective teaching of physics requires the use of well-designed and diversified instructional tools such as multimedia throughout the teaching and learning process. The main objective of this study was to investigate the effectiveness of Physics Educational Technology (PhET) simulations and YouTube videos to improve the learning of optics in Rwandan secondary schools. The study was framed by the cognitive theory of multimedia learning. A total of 136 senior-4 physics students from six schools were divided among three groups and taught with the usual teaching methods only, the usual teaching methods supported by PhET simulations or YouTube videos, respectively. Student achievement was measured by administering the Geometric Optics Conceptual Understanding Test to each group of students before and after teaching. The groups of students who were taught using PhET simulations and YouTube videos achieved significantly more gains on the posttest compared with the students who experienced neither. PhET simulations and YouTube videos saw average normalised learning gains of 12 and 11%, respectively, while students who experienced solely the usual teaching methods got a gain of only 2%. These results show that the use of PhET simulations without student manipulation (as applied in this study) is equally effective as the use of YouTube videos. The researchers recommend that teachers incorporate these instructional tools as a way of effectively teaching and learning optics.

中文翻译：

---

PhET模拟和YouTube视频对改善卢旺达中学光学学习的有效性

有效的物理教学要求在整个教学过程中使用精心设计和多样化的教学工具，例如多媒体。这项研究的主要目的是调查物理教育技术（PhET）模拟和YouTube视频对改善卢旺达中学光学学习的有效性。该研究以多媒体学习的认知理论为框架。来自六所学校的136名高四物理专业学生被分为三组，并且仅使用通常的教学方法进行教学，这些方法分别由PhET模拟或YouTube视频支持。通过在教学前后对每组学生进行“几何光学概念理解测试”来衡量学生的成绩。与没有经历过的学生相比，使用PhET模拟和YouTube视频教过的学生在后测中获得了明显更多的收获。PhET模拟和YouTube视频的平均标准化学习增益分别为12％和11％，而仅使用常规教学方法的学生仅获得2％的增益。这些结果表明，在没有学生操纵的情况下使用PhET模拟（在本研究中应用）与使用YouTube视频同样有效。研究人员建议教师们将这些教学工具结合起来，以有效地教与学光学。PhET模拟和YouTube视频的平均标准化学习增益分别为12％和11％，而仅使用常规教学方法的学生仅获得2％的增益。这些结果表明，在没有学生操纵的情况下使用PhET模拟（在本研究中应用）与使用YouTube视频同样有效。研究人员建议教师们将这些教学工具结合起来，以有效地教与学光学。PhET模拟和YouTube视频的平均标准化学习增益分别为12％和11％，而仅使用常规教学方法的学生仅获得2％的增益。这些结果表明，在没有学生操纵的情况下使用PhET模拟（在本研究中应用）与使用YouTube视频同样有效。研究人员建议教师们将这些教学工具结合起来，以有效地教与学光学。