Learning in double time: The effect of lecture video speed on immediate and delayed comprehension

Abstract

We presented participants with lecture videos at different speeds and tested immediate and delayed (1 week) comprehension. Results revealed minimal costs incurred by increasing video speed from 1x to 1.5x, or 2x speed, but performance declined beyond 2x speed. We also compared learning outcomes after watching videos once at 1x or twice at 2x speed. There was not an advantage to watching twice at 2x speed but if participants watched the video again at 2x speed immediately before the test, compared with watching once at 1x a week before the test, comprehension improved. Thus, increasing the speed of videos (up to 2x) may be an efficient strategy, especially if students use the time saved for additional studying or rewatching the videos, but learners should do this additional studying shortly before an exam.However, these trends may differ for videos with different speech rates, complexity or difficulty, and audiovisual overlap.

Going beyond the spacing effect: Does it matter how time on a task is distributed?

“…Given that flexibility, some students may watch lecture videos a single time at their original speed, while others may watch a given lecture video more than once and perhaps at an increased speed. Thus, two students may spend the same amount of time watching a particular lecture video but differ in how that time is distributed (see Murphy et al., 2022b, for a test of this conjecture).…”

Speeding lectures to make time for retrieval practice: Can we improve the efficiency of interpolated testing?

“…Similarly, Nagahama and Morita (2018; see also Nagahama & Morita, 2017) increased the playback speed of a lecture by 1.5× and 2× and found no significant performance cost on a test of the lecture material relative to the original speed. That said, increasing the playback speed of lectures does have costs when the playback speeds increase beyond more modest levels (Jacobson et al, 2018; Murphy et al, 2022). For example, Murphy et al (2022) compared lecture speeds of 1×, 1.5×, 2×, and 2.5× and found no performance costs up to 2× but a clear performance cost at 2.5×.…”

Has pedagogy, technology, and Covid‐19 killed the face‐to‐face lecture?

“…This includes understanding the potential purpose and advantage, or not, of continuing to incorporate some lecture elements either face‐to‐face or online. In terms of encouraging online lectures only, one could argue that if a 50‐ to 60‐min face‐to‐face lecture, where it is focused on information transmission, fails to engage most students then transferring to an online format will be an even worse experience and may explain why some students already watch lecture recordings at faster than normal speeds (Murphy et al, 2021 ). Being able to access learning resources anytime and anywhere does not mean that putting a resource online will mean it will be effective and instead all online learning resources including those that have lecture‐style components must be carefully and thoughtfully designed for and be accessible to the online learner and also take account of the changing learning needs and preferences of students.…”