Subtitles: on or off?

It’s clear that under 30 year olds use subtitles habitually when watching TV and movies, both for content in unknown languages, like Squid Games, but increasingly for content in their own languages (Young, 2021). It’s a subject that everyone has ideas about – why people like using them, parents complaining that their children only use them because they are on their phones.. that aside we also know that the majority of students use subtitles when ‘catching up’ with missed live content. What our research focused on was the effect on learning of using subtitled recordings, and in particular the effect of using subtitles with live recordings of lectures.  We know from student feedback that a substantial minority primarily view taught content this way. If this is you, and you want to remember what you’ve watched, should you switch the subtitles on or not?

To address this question we adopted an experimental approach, comparing immediate memory of the material covered in a ten-minute lecture extract either from unfamiliar Psychology content or from a Biochemistry lecture. Automated transcripts were corrected to ensure that the spoken content matched subtitles as closely as possible. Our experiment was a between groups design, and each participant saw either the Psychology or the Biochemistry lecture content with or without subtitles. We collected demographic data about hearing, whether students used English as their first language and whether they had high school level familiarity with Psychology or Biology. In this first experiment, we found that there was small disadvantage for immediate recall when subtitles were used in a mixed-models analysis. This disadvantage for subtitled extracts was unaffected by demographic factors, although those students who have English as an additional language generally recalled fewer details from the lecture extracts. Speculative explanations include those related to increased cognitive load when you attend to two different channels of information.  We are currently conducting follow-up experiments, here and at other universities across the UK! If you want to find out more please email sam.mccormick@rhul.ac.uk