Subtitles in the classroom: Balancing the benefits of dual coding with the cost of increased cognitive load

Abstract

Language teachers in the twenty-first century cannot ignore the possible benefits of using multimodal texts in the classroom. One such multimodal source that has been used extensively is subtitled videos. Against the background of conflicting theories in the fields of educational psychology and psycholinguistics as well as language acquisition where multimodal texts are concerned, this article presents an experiment aimed at  determining the impact of competition between different sources of information on comprehension and attention allocation. The material that is investigated is a recorded and subtitled academic lecture in Economics
with PowerPoint slides edited in, as an example of multisource  communication. The article in particular engages with the issue of language as it pertains to the use of English as medium of instruction for English Second Language (ESL) students in South Africa. Essentially, the article seeks to shed light on the well documented positive effects of subtitles that are explained by the information delivery hypothesis and Dual Coding Theory, and the equally well documented negative impact explained by the redundancy effect in Cognitive Load Theory. Some
evidence was found in the study that cognitive resources are assigned to more stable information sources like slides and non-verbal visual contextual information when the presentation speed of subtitles increases. This means that when the presentation speed of subtitles increases,
learners focus on stable textual information (like slides) and on nonverbal information (like the face of the lecturer). Using the correct presentation speed of subtitles in multisource information in an educational setting is imperative for the activation of the potential benefits of multisource communication (that includes subtitles) for learning. The findings of the study stand to benefit all fields of multimedia educational design, but also have direct relevance to the use of technological support such as subtitles in the classroom.

Key words: cognitive load, dual coding, information delivery, multimedia
educational design, subtitles