Abstract
Video captioning has been investigated extensively in the Computer-Assisted Language Learning (CALL) literature to aid second language vocabulary acquisition. However, a little is known about how video captioning could foster learners' pronunciation, which is a component of second language vocabulary acquisition proposed by Nation (Nation, Learning vocabulary in another language, Cambridge University Press, 2001), when attending to video captioning. Therefore, this study aims to investigate the effect of two types of video captioning, namely, full versus partial captioning, on mastery of word pronunciation. Furthermore, we tested the magnitude of the cognitive load imposed by video captioning types using NASA TLX. A total of 55 Arab English as a Foreign Language learners watched videos with full, partial or no captioning. Their perceptions about learning with captioning were also surveyed. Results of the pre-post-tests indicated that the captioning groups' performance in the pronunciation tests outscored the no captioning group. In turn, the partial captioning group's scores were slightly higher than those of the full captioning group. However, this difference was statistically insignificant. Cognitive load was found higher in full captioning and no captioning than that in the partial captioning mode. The participants showed highly positive attitudes towards learning with captions.