Producing Educational Videos: A how-to guide

Part 1 - How long should your video be?

I am currently conducting research into how my students have engaged with asynchronous videos in their studies. If you are unfamiliar with the terminology, these are video recordings used to support your students, that are made available to watch either before or after your in-person teaching, or perhaps before a deadline for a piece of work. These differ from synchronous videos which are recordings of your in-person lectures, used for revision purposes or to help those that were unable (or unwilling) to attend the timetabled session.

Video recordings of lectures have grown in popularity since the late 2000s, and have become standard practice in many institutions in the last ten years. Asynchronous videos have been around in some form for a long time, but have really become normalised since the lockdowns of 2020 onwards. Indeed my research in this area uses data from 2020-22 of student access to my lecture recordings where this was the only access they had to lectures whilst we were not running live sessions. At De Montfort University we now have a model where we have both two hours a week of live lectures (which are recorded as well), and two hours a week of asynchronous videos recorded.

To provide some context from my data, for the 20-22 period I studied for two of my modules, the average student watched around one third of the minutes of lectures that they had access to and the average video was viewed at all by less than half of the cohort. Engagement was therefore low, and this is replicated in more recent modules, this provides part of the motivation for understanding the patterns of student engagement with this content.

With all this going on, and videos of various kinds becoming a major part of university education, understanding what best practice is around the production of these videos is an important topic, and one I hope to contribute to. In these posts I will set out some rules to follow based on my experience producing videos, my understanding of the literature and my research in this area to date¹.

Rule 1 - Keep it Short

Prior to 2020 the only videos I had ever made were just lecture recordings of sessions I had given to live audiences. As a result my videos were normally 45-50 minutes long, reflecting my standard lecture length. When we switched to making asynchronous online videos in 2020, amidst the various tips and bits of training, one of the most common messages was to split out lectures into ‘chunks’ of 10-20 minutes. It is this process that underlies my current research, which is comparing engagement with longer single videos, to ones where the videos have been split into two or three shorter chunks.

Was this advice underpinned by evidence? In this case, yes it was. There is a large literature which supports the idea that shorter videos are more likely to be watched, and watched for more time. What is an ideal length?

Guo et al (2014) is perhaps the most comprehensive analysis on this subject, and one I will draw on heavily here. The authors review millions of views from online courses for patterns of engagement, which in specifically means the amount of a video viewed, and whether interactive questions or other elements are attempted. The recommendation they come to is that videos be no longer than 6 minutes. The reason for this recommendation is that in their data, average engagement drops off sharply for longer videos. Other authors recommend maximum lengths of 10 minutes, or 20 minutes for similar reasons.

Two explanations can be given for why short videos see higher engagement. The first is underpinned by cognitive load theory. A learner can only process so much information at once, after a few minutes we will get distracted, and not absorb information properly, so a shorter video is preferable.

A second explanation is that shorter videos are likely to be better planned and edited, to be focused and concise. Therefore the higher engagement with shorter videos is in part picking up a measure of quality, rather than being to do with time per se.

A caveat

Before committing to short videos, let me raise a caveat. There are lots of long videos out there that get plenty of views. Many of my 50 minute videos have plenty of people watching them all the way through. Guo et al’s and other results are based on the fact that some of the cohort stop watching after a certain point. But that doesn’t mean that many of the other students might be benefitting from the longer form. Should we be designing our videos around those with the shortest attention spans and most limited capacity to learn.

Consider this quote from Andrej Karpathy, an AI specialist who produces educational videos of very high quality that are normally several hours long:

There are a lot of videos on YouTube/TikTok etc. that give the appearance of education, but if you look closely they are really just entertainment. This is very convenient for everyone involved : the people watching enjoy thinking they are learning (but actually they are just having fun). The people creating this content also enjoy it because fun has a much larger audience, fame and revenue. But as far as learning goes, this is a trap. This content is an epsilon away from watching the Bachelorette. It's like snacking on those "Garden Veggie Straws", which feel like you're eating healthy vegetables until you look at the ingredients.

Learning is not supposed to be fun. It doesn't have to be actively not fun either, but the primary feeling should be that of effort. It should look a lot less like that "10 minute full body" workout from your local digital media creator and a lot more like a serious session at the gym. You want the mental equivalent of sweating. It's not that the quickie doesn't do anything, it's just that it is wildly suboptimal if you actually care to learn.

I find it helpful to explicitly declare your intent up front as a sharp, binary variable in your mind. If you are consuming content: are you trying to be entertained or are you trying to learn? And if you are creating content: are you trying to entertain or are you trying to teach? You'll go down a different path in each case. Attempts to seek the stuff in between actually clamp to zero.

So for those who actually want to learn. Unless you are trying to learn something narrow and specific, close those tabs with quick blog posts. Close those tabs of "Learn XYZ in 10 minutes". Consider the opportunity cost of snacking and seek the meal - the textbooks, docs, papers, manuals, longform. Allocate a 4 hour window. Don't just read, take notes, re-read, re-phrase, process, manipulate, learn.

And for those actually trying to educate, please consider writing/recording longform, designed for someone to get "sweaty", especially in today's era of quantity over quality. Give someone a real workout. This is what I aspire to in my own educational work too. My audience will decrease. The ones that remain might not even like it. But at least we'll learn something.

Consider this video, also on computer science topics, from a Harvard lecturer:

It is almost 26 hours long (no I haven’t watched it all!)

But it has 3.4 million views. Now not many of those have probably watched the whole thing through, but I bet many hundreds of thousands have watched multiple hours of this, and there are hundreds of positive comments. In fact there are entire other videos on YouTube, themselves 10-20 minutes long that act as a guide to how to watch this video!

It is clearly not the case that people don’t want to watch long videos. People still go to the cinema and watch two hour long movies, or binge multiple hours of TV series, as well as read for long periods.

So there should be a note of caution, yes some people will stop watching if a video is too long, but some points do take longer to make, and we should not be afraid of pushing our better to students to concentrate. Of course it is also easy to pause videos and come back to them where needed (something I do all the time), so no-one needs to lose out from a longer video.

What I do

Given all that, what do I do, and what would I recommend?

I aim to keep my asynchronous videos to about 20 minutes as a maximum. I find this normally gives me enough time to clarify an element of analysis that I want to do, whilst forcing me to think carefully about clarity and conciseness.

These videos are then organised into sets, so I normally will have a set of three videos to begin a new topic, each 10-20 minutes long to give me 40-60 minutes of total time.

I find that for most purposes, a time of less than 10 minutes is too restrictive. I also do not want to be making videos of many hours. Evidence as well as intuition tells me that most people cannot watch and absorb information for very long periods. In the examples in the previous section, despite their length, the videos were really compilations of lots of mini points (literally so in the case of the Harvard lecture, which was a compilation of many weeks’ worth of videos), and most people will be watching in chunks anyway.

Between the mini video of 6 minutes, and the mammoth one of 26 hours, I will opt in most cases for a happy medium.

In the next part I will discuss other aspects of the quality of a video, demonstrating how to implement features identified in the research that enhance learning and attainment.

1. My research is ongoing, so I may need to come back and update this if further findings contradict anything I say here.