Captioned video for L2 listening and vocabulary learning: A meta-analysis

This study reports on a meta-analysis of the effectiveness of captioned video (i.e. L2 video with L2 subtitles) for listening comprehension and vocabulary learning in the context of second language acquisition. The random-effects meta-analysis provides a quantitative measure of the overall effect of captions on listening comprehension and vocabulary acquisition, as well as an investigation into the relationship between captioning effectiveness and two potential moderators: test type and proficiency level.We conducted a systematic review and calculated effect sizes for 18 retrieved studies. Separate meta-analyses were performed for listening comprehension (including data of 15 studies) and for vocabulary learning (including data from 10 studies). The findings indicate a large effect of captions on listening comprehension as well as on vocabulary acquisition. Test type was found to moderate the effect sizes of listening comprehension. Proficiency level did not moderate the effect sizes of listening comprehension and vocabulary learning. The article concludes with a contextualized discussion of the results and an overview of the limitations of the present meta-analysis as well a number of future research perspectives.