Video for learning –15 things the research says – some may shock you…
Author: Donald Clark
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Video for learning is great at some things, not so great at others. Some time back I attended a session on video for learning and found that neither the commissioners nor the video production company had looked at a single piece of research on video and learning. They told us that people loved the work and since then I’ve seen a lot of ‘Netflix for learning’ delivery. That’s fine but let’s step back a minute..What I didn’t see was much evidence that people were actually ‘learning’ much. I have been involved in video production for 35 years, from corporate videos delivered on VHS cassettes, interactive videos on Laservision (in many ways way beyond what we currently see), CD-ROMs and now streamed. We even made a feature film The Killer Tongue – lost a pile of money on that one and lesson learnt.
What can we learn from Netflix?
It wiped out Blockbuster and has become a behemoth in the entertainment industry because it adopted a demand-AI-driven, technological and personalised solution in a world that was stuck in scheduled, supply-side delivery. Netflix is easy to use, searchable and personalized, extensively A/B tested, tiled and has an AI recommendation engine behind the interface. It is also time-shifted, streamed and multi-device. But what really makes it sing is the data-driven algorithmic delivery. This is why learning and video folk need to pay attention to technology, especially AI. That other behemoth, YouTube, the largest learning platform on the planet, is also searchable, personalised and time-shifted.
Episodic v semantic memory
Many can recall famous scenes from their favourite film. Mine is the Rutger Hauer scene from Bladerunner, where he sits, dying on the roof in the rain and gives a moving soliloquy about the joys of life, forgiveness and death. Many recall the scene well but few can remember what he actually said. That is because our episodic memory is strong and video appeals to that form of memory, but video is terrible on semantic knowledge, what we need to know in terms of language. I can remember the scene and literally play it back in my head but I can’t remember the speech. This is why video is not so good at imparting detail and knowledge. There is a big difference between recalling episodes and knowing stuff. Yet so often we see talking heads and text on screen that tries to do exactly that.
Shooting star
Learning is a lasting change in long-term memory and video suffers from the lack of opportunity to encode and consolidate memories. Your working memory lasts about 20 seconds, can only hold three or four things in the mind at one time and without the time to encode it is quickly forgotten Sweller (1988). Our minds move through video like a shooting star, where the memories burn up behind us. Without additional active, effortful learning, we quite simply forget. A big warning here, people think they have learnt from video but as Bjork (2013) and many others have shown, much of this is illusory learning, mistaking the feeling that you’ve learnt things but when tested, you have not.
How long do learners engage?
We know from Guo (2014), who had a large data set of learning video data gathered from MOOCs, that learners drop out in large numbers at around six minutes. It drops dramatically down to 50% at 9-12 minutes and 20% beyond this. Evidence from other studies on attention, using eye-tracking, confirm this quite rapid drop in arousal Risko (2012). Keep videos at 6 minutes or less – the less the better.
Student control of video?
Should you give learners control of video? Yes. In fact giving them ‘chapter’ points beyond the usual forward, back and pause controls proves useful, as it matches the structure of the learning experience Zhang (2006).
Video, audio, text on screen?
It is vital to reduce cognitive load in video. Mayer (2003) and others have shown that text plus audio plus video on the screen, commonly seen in lecture capture, actually inhibits learning. Don’t put captions, text or scripts on the screen while the narrator or person on the screen is talking. One exception to this (rules are there to be broken) is in language learning, where the ability to jump from voice to text can prove useful. Also avoid complex backgrounds and background music, as they also inhibit learning Brahme (2016).
Talking heads or not?
This comes as a bit of shock to many but talking heads, that staple of lecture capture and MOOCs, is often not such a great idea. It can be useful if the person is a respected and well-known expert and there is evidence that the mere knowledge of them as famous experts increases retention and there is a social learning effect. Inspirational talks, well-delivered with emotional impact can also work. But there is nothing worse, in terms of learning that an autocued talking head, mechanically delivering a scripted piece to camera in the expectation that people will remember what he or she has said – they won’t Chaohua (2019). We have ample evidence for this in the Khan Academy where you don’t see Salmon Khan’s face, only the working through of examples or images. Cognitively, the face is often just noise, what you want to see is the actual maths. Similarly with the hand drawing and writing on screen. For subjects that are semantically rich, getting rid of the face is a good thing as it reduces cognitive load.
Recommendations on speech?
Perspectives in learning video?
When showing the manipulation of objects by hand or, in general, procedures and processes, video shot from the perspective of the learner, is better that third-person viewpoints. This may upset traditional Directors but it means that you get cognitive congruence Florella (2017).
How does image size affect learning?
This should worry those whose video as a great medium on smartphones. The smaller the screen the less you learn. Or the larger the screen the more you learn. Nass and Reeves (1996) showed 60 video segments to 125 adults on different screen sizes and tested them a week later. Those that had watched the larger screen remembered “significantly more”.
How does video quality affect learning?
Video quality doesn’t appear to matter as much as audio quality. That’s because our vision has evolved to cope with twilight, different light conditions and so on. Our hearing, on the other hand, is designed for close proximity speech Nass and reeves (1996). Their research showed that on attention, memory and evaluation, video quality had “no psychological advantages” whereas audio quality was critical.
How do video cuts and pace affect learning?
Cuts raise attention, about 1 sec after the cut but too many cuts lowers attention
Should we chunk video?
OK here’s the big one. Learning improves when there are “visual rests” and memory is enhanced when ”people have a chance to stop and think about the information presented“. We need to stop and think about that a little. It seems as though micro-chunking video down to smaller segments is a good think for learning Florella (2019).
