What video can and can't do for education

At the start of this year, I left the classroom to work full-time for the YouTube channel 3Blue1Brown. No introduction necessary to those who read this blog, I presume.


Why would I eschew a well-paying teacher position in Switzerland to go work at a scrappy start-up? Isn't "I wanna be a YouTuber" the new "I'll become a rapper anyway"? 

Here I expose my reasons for joining 3Blue1Brown. In a follow-up post, I will explain why working full-time in the classroom, as much as I enjoy it, is incompatible with the contributions to math education I hope to achieve.

In its self-description, 3Blue1Brown creates "animated math" – also in the original sense of the word of bringing life to something. Its videos are the best conveyors of what mathematical objects look like before the "mental eye" I have ever seen. No static image, not to mention a written text or string of symbols, comes close to its visual and dynamic immediacy. The videos show, don't tell, what a textbook can't or just won't.

Another aspect I have always admired is Grant's quest for visual interpretations where most others would simply shrug and say "It's just a formula, shut up and calculate." If only as a mental exercise, I have found such a self-imposed challenge extremely helpful for gaining insight into both the mathematical content itself and how to teach it. I owe this dedication to the iconic mode of thought to the eye-opening work of James Tanton.

A good picture can not only illustrate a formula or theorem, but even bypass whole calculations. Many page-filling textbook proofs could be supplanted entirely by a single well-crafted picture or animation. Granted, formal symbolic proofs and calculations bring the unmatched precision and expressiveness one needs to e. g. design a matching computer program. However they lack the clarity, accessibility and humaneness of pictures. The art of visual thinking has been sidelined in favor of symbolic manipulations ever since the invention of the printing press, followed by the various formalist schools and the advent of programming languages. As much as these developments have helped advance humanity technologically, they have also widened whatever gap there already was between the math "haves" and "have-nots" into a gaping canyon. It has catalysed similar divides throughout related fields. But the times of innocence when we could bask ourselves in the "Cult of the Expert" are long gone. This is an unsustainable situation, and the resentment it creates can be seen daily in the news.

Ok, back to math now.

If you look around on YouTube for educational math videos, most of them are just a person in front of a board, doing the age-old "chalk and talk". This is old wine in new wineskins. 3Blue1Brown is one of very few channels that actually harness the new capabilities of the new medium. Sure, other channels have flashy transitions and effects, cute cartoon characters and upbeat presenters, but the content proper is still mostly static and symbolic – glorified textbooks.

But well-crafted exposition videos can do a much better job at conveying mathematical understanding than textbooks. Far from me to claim they could ever replace the human connection that only a teacher in flesh and blood can provide. After all, teaching is so much more than just explaining. Still, the prevalent ways of explaining alone are in dire need for improvement.

Despire the (warranted) calls for differentiation and personalized learning, I think there is a case to be made that some explanations are objectively better than others. The multitude of good teaching practices and learning situations, not to mention the spectacular failure of New Math, have dampened our expectations of finding the One True Way of teaching any particular concept. And while that is a sane position, such a culture of “Anything goes” (content-wise) can keep us from seeing the potential for genuine and substantial progress in rethinking content and overcoming historical baggage.

What was perhaps most striking to me when I stumbled upon 3Blue1Brown is the fact that Grant has no formal teacher training, “only” tutoring experience. Yet he has managed to internalize many  valuable skills and practices that many accredited teachers lack. They took me a long time to figure out as well, if only because they are not (cannot be?) taught in teacher training to any meaningful extent. Things such as an acute sense of visual design, cognitive load, and simple yet precise language. How to tell a compelling story, how to use subtle visual cues such as color and positioning to convey meaning nonverbally. How to recognize and question perpetuated traditions and hidden assumptions. Such talent is sorely lacking in our culture of communication, and especially in education.

Videos in the style of 3Blue1Brown are a big first step in the right direction. This is the reason why I took the opportunity to do everything I can to help expand its library, and develop whatever form its content may take in the future. If you are curious what next steps I think should follow in the world of math education, take a look at the visionary works of Bret Victor and Keith Devlin.