Can we learn from recorded lectures when they fly by at double speed?

Caitríona Ní Shé of Academic Practice reflects below on the use of 2 x speed in replaying recorded lectures.

I have long since been aware of the value of playing instructional videos (how to’s etc) at 2x speed, but it was only recently that I considered the impact that this might have on higher education. With the onset of the pandemic, and the move to online teaching and learning, many educators either pre-recorded lecture material or recorded their live online lectures, and then them made available to students on the institutional Virtual Learning Environment (VLE).

What if students continued habits that they had developed when engaging with everyday web content and engaged with their lecture materials at 2x speed? Would they miss salient points from the lecture? Would they retain the knowledge imparted? Or would they fail to achieve the desired learning outcomes?

As the pandemic arrived, my own children in higher education moved from physically attending live lectures to accessing online and recorded lectures. Their lectures were available to download and watch at a time that suited them. I observed suspiciously from the side-lines, as they watched and listened to recorded lectures at 2x, sometimes pausing and replaying, but generally flying through the lectures as fast as they could! And it turns out that they were not alone. Anecdotally, students (including those attending Trinity) reported that they regularly watched recorded lectures at 2x speed.

A current UCLA study into the effects of video speed on comprehension was the topic of an RTE radio piece on the Drivetime programme early in the new year [1]. An incredulous host, Cormac Ó hEadhra, cast a sceptical eye on the whole notion, wondering ‘what type of a course are you doing if you can listen at double speed and take… specific details in?’ However, his co-host, Sarah McInerny, was not so sceptical and suggested that playing back at higher speeds may force the students to concentrate harder, and ultimately save students’ time. Megan O’Connor, Deputy President of the USI and a guest on the show, said she that while she never listens herself at double speed, she knows of people who do this and wasn’t against the idea. Megan suggested that students should be allowed adapt their learning techniques to suit their personal needs, and that all lectures should be recorded and made available as standard practice.

Recognising that there are many variables to consider when evaluating the use of 2x recorded lectures, UCLA conducted a series of experiments to determine the immediate and delayed comprehension of students who watched recorded lectures at varying speeds (1x, 1.5x,2x and 2.5x) [2]. Between 100 and 230 students participated in each experiment and sat the subsequent comprehension tests. A control group of 123 students were asked to complete the same tests without watching the videos. Even though previous work in this area had reported mixed results, this study found that immediate and delayed comprehension was not affected by watching videos at either 1.5x or 2x. Thus, they suggest that students may put the time saved, by watching recorded lectures at 2x, to educationally beneficial use. Additionally, students who watched the videos twice at 2x speeds, with a week’s delay in between each session, performed better in the comprehension tests than those who had watched the recorded lecture once at 1x, thus demonstrating the strategic value of 2x. Finally, 85% of the control group reported normally watching their lectures at speeds of greater than 1x.

Therefore, the answer to the question ‘Can we learn from recorded lectures when they fly by at double speed?’ is Yes, we can!

Having come from a position where I considered that using 2x on a ‘how to…’ video is vastly different than listening to a lecturer explain the concepts of group theory or differential equations, when surely you need to listen at 1x to catch every syllable the lecturer makes, I am now convinced. Using 2x may indeed be a strategic learning technique that saves time for students and supports the request by students that all lectures are recorded and made available on VLEs.

And loath though I am to say this, my kids have been correct all along, 2x works, even in the context of recorded lectures in higher education.

[1] Ó hEadhra, C. & McInerny, S. (2022, January 18). Fast Forwarding your lectures could actually be good for your learning. [Radio Broadcast].

[2] Murphy, D. H., Hoover, K. M., Agadzhanyan, K., Kuehn, J. C., & Castel, A. D. (2022). Learning in double time: The effect of lecture video speed on immediate and delayed comprehension. Applied Cognitive Psychology, 36(1), 69-82.