Universities around the world are incorporating online learning, often relying on videos (asynchronous multimedia). We systematically reviewed the effects of video on learning in higher education. We searched five databases using 27 keywords to find randomized trials that measured the learning effects of video among college students. We conducted full-text screening, data extraction, and risk of bias in duplicate. We calculated pooled effect sizes using multilevel random-effects meta-analysis. Searches retrieved 9,677 unique records. After screening 329 full texts, 105 met inclusion criteria, with a pooled sample of 7,776 students. Swapping video for existing teaching methods led to small improvements in student learning (g = 0.28). Adding video to existing teaching led to strong learning benefits (g = 0.80). Although results may be subject to some experimental and publication biases, they suggest that videos are unlikely to be detrimental and usually improve student learning.

世界各地的大学通常都依靠视频（异步多媒体）来整合在线学习。我们系统地回顾了视频对高等教育学习的影响。我们使用27个关键字搜索了五个数据库，以找到可测量大学生视频学习效果的随机试验。我们进行了全文筛选，数据提取以及重复出现偏倚的风险。我们使用多级随机效应荟萃分析计算了合并效应的大小。搜索检索到9,677个唯一记录。在筛选了329篇全文之后，有105篇符合入选标准，并汇集了7776名学生。将视频替换为现有的教学方法会导致学生学习方面的小改进（g = 0.28）。将视频添加到现有教学中可带来强大的学习优势（g = 0.80）。