Why Sal Khan't: On Learning by Making but Teaching by Telling
punyamishra.com83 points by the-mitr 5 hours ago
83 points by the-mitr 5 hours ago
Overall, I do agree with the thesis but:
> Now… how does Sal Khan want my kid to learn?
> Watch a video.
I find this a little uncharitable. I learned a lot of math at a young age from Sal Khan's early videos (back when he used to erase by switching to a black pen and scribbling across the entire screen) and, to put it in the author's terms, it served as an easy-to-digest scaffolding on top of which to build a deeper understanding. I don't think Khanacademy ever sold itself as a magic learning resource that removes the need to work out problems yourself.
The attacks on Khan here personally irked me.
I grew up in a small rural town where math teachers were rare and good ones were nonexistent. I still remember watching Sal Khan's videos on calculus after struggling to get any grip on it, and coming back with a fire in me because for the first time he exposed me to the beauty of calculus. I remember teaching my friends in the library using exactly what Khan did in his videos.
This guy is completely wrong about Khan not inspiring students to care. Sometimes all students need is to see what caring looks like to ignite it in themselves, and Khan did that for millions.
Yes, exactly. I have also learned a lot of math, grammar, science, and other subjects from Sal. In most videos, Sal explicitly states to pause the video and try out the problem before he works through it. I do think that KA's style of teaching needs some getting used to (this was never a problem for me as it was one of my first teaching platforms). However, once you get used to it, it is a wonderful experience.
I don't agree and the hype surrounding his efforts was something much greater than what KahnAcademy actually is (a very useful resource).
He sold his vision in "The One World Schoolhouse" which was essentially global learning via all the best videos (and one unified curriculum) you can make and teachers effectively being technicians/teaching assistants. It was the vision that utopian minded technologists craved in the early aughts.
It's not a bad idea in concept, but the core problem is what he delivered was:
"essentially global learning via all the Khan videos, in math, by him, and in other subjects, by his team."
Khan Academy is 2010-era state-of-the-art for rote learning and procedural knowledge. That's a helpful resource, but as one world schoolhouse, there is:
- No room for creativity, or much of anything similar from students (outside of the fantastic JavaScript projects).
- No room for outside innovation.
- A personality cult. Any ideas MUST be attributed to Khan.
Creativity isn't learning, it's the application of learning, and that's not what school is for. There has always been value in somebody showing you how to apply a math technique and practicing using it to solve problems. It's not creative but it gives us the skills to do useful things in the world - including creative things. Even pure rote learning (such as reciting the periodic table) is useful so you can later draw on that knowledge without interrupting your attention on the higher level thinking (such as creativity!) that you're doing.
Side note, but much as I like Khan Academy overall, I've always struggled with Sal's slow and repetitive speaking style in the videos.
"Now you add the five ... [pause] ... add the five ... add the five to the seven ... to the seven..."
Running them at 1.5 - 2x helps a bit, but it's still annoying to the point that I find it very distracting.
While it depends entirely on personal opinion, I believe that it helps significantly. It helps build up the problem/solution from the ground up and he goes through each step out loud to help a student understand. I get that some people hate it and think it is so childish for such simple steps. For other people, it helps a lot. Learning on KA works best if started aat a young age and done consistently (you get used to the style and you learn everything from the ground up).
In my case, it's not so much that I find it childish, it's that I find it incredibly distracting which means I can't focus as easily on the content. Instead of "oh, now I understand how that equation works" I catch myself thinking "why is he repeating the same word over and over - that's so annoying!". Then my brain starts obsessing over "when is he going to do it again?", even though I don't want it to. It's a bit like trying to deliberately ignore something. It becomes all you can think about.
OTOH creating neural connections takes time. It's a real distance. Small for us, but great for the cells. That's why explaining difficult concepts too fast, while cool for people getting things instantly, is not good for general population.
I very much agree and it saddens me often when I see folks dial it up to 1.5x or 2x "because it is boring otherwise". They might think they just get as much, only in half the time, but I'd hypothesize that they retain less because the mind needs some time to digest.
Similar with the trend to auto-cut pauses that speakers make, just to cram in more text into a youtube video. Destroys not just the pacing but any chance for the mind to take its time.
I'd love to see studies about this.
I don't think you can make blanket statements. Consider:
1. Teacher 1 speaks at 100 words per minute.
2. Teacher 2 speaks at 50 words per minute, for the exact same content as Teacher 1.
You're not really losing anything by playing Teacher 1 at normal speed vs Teacher 2 at 2x speed. For every learner, there will be an optimal teaching speed for a given topic. This may mean listening to some audio at normal speed, some at higher speeds, and some even at slower speeds. I always customise my playback speed to the specific content I'm trying to learn.
There's a difference between pacing (good), and repetitive speech (bad). Between pacing and repetitive speech.
Ironically, spaced repetition is the key to successful learning.
Obviously one can overdo it. And there is variance in what people require. But not giving things time, instead giving in to the dopamine-craving, that's killing your learning abilities.
I originally learned linear algebra from Gilbert Strang's OCW videos, and I was only able to stick with them by 2x'ing the playback rate; at this point, hearing Strang at his normal speaking rate sounds to me like hearing him after a Robitussin bender.
This is exactly what my kid said about why he doesn’t like Kahn academy.
What would you recommend over khan academy?
I've not tried it myself, but I consistently hear good things about Math Academy. It uses a knowledge graph so that it knows whether you've satisfied prerequisites for a topic, and it adapts itself to your level. I've never taken the plunge because it's very expensive at $49 a month, but it seems to be the one that serious maths learners use.
I did the trial of Brilliant the other day. You can get 7 days free, then another 7 days added if you cancel the first trial before the end. After that you can continue to get 2 free lessons per day with ads. I think it's about $20 a month for unlimited lessons. The maths problems are more visual (which makes them quite intuitive) and it has a nicer, more polished UI than Khan Academy. It's easier to stay in the mood for doing more lessons. The main downsides compared to Khan are that the explanations are quite minimal (short descriptions, no videos), and it doesn't reach as advanced a level as Khan. I'm looking at it as more a way to do a refresher on the maths I already learned at school rather than a serious learning tool. If it were $5 a month I'd probably consider subbing for a couple of months and trying to blitz through all the material before switching back to Khan to fill in the gaps.
While I am a strong supporter of KA, I just use regular schooling to review and back up what I learned on Khan.
Khan Academy is a treasure, and is how I re-learned math in my 20s after not taking it seriously in school. Then moved on to MitX for science [re]fam.
I am having my kids learn math with Kahn academy if we don't have anything better by that point.
The article is indeed uncharitable. Nowhere does the article mention the fact that there are exercises AND that you can explore the website and the different resources in the way you like. You don't even need to watch videos if you don't want to.
You also do not need to linearly follow the topics/videos. You can take a few quizzes from some topic, notice you don't understand something completely yet and instead pick up more trigonometry instead.
I've worked through Khan academy in a way similar to what the author describes as a good flow, but then all within the Khan Academy platform. The platform even allows for discussions and questions.
To me the problem is much more that motivation or a destination is not something that Khan Academy will give you. Then again, so won't most teachers. I much preferred Khan Academy over most of my math teachers, but occasionally I've had teachers who helped me love a subject I barely knew beforehand.
My understanding is that the idea behind Khanacademy is to switch the classroom -- learn a topic as homework; do the questions in the classroom. That way the teacher can assess (and help) the students.
The other idea is that a student only advances to the next topic once they've mastered the current topic (e.g. by getting 4/5 questions right). The theory behind this is that if you don't understand a concept/topic then it is harder to understand topics that depend on that.
This does mean that students will be at different topics/stages. But because of the structure of the teaching a teacher isn't moving on to a new topic leaving students to fall further and further behind.
The idea of Mastery Learning seems to resurface every couple decades. I guess because it pretty appealing but requires more per-student customization; there’s always a hope that now, finally, we’ve got the tech to let everyone advance at their own pace.
IDK. Maybe some sort of RAG-on-textbook solution will let us do it.
The idea is for the students to watch the videos outside of class and this frees up time for the teachers to provide individual help.
From what I know of the Khan approach, it's akin to "flipping the classroom" [0], which has gained pretty wide acceptance.
(I use the flipped classroom approach extensively. But the legal profession being the eager embracers of novelty that we are </sarcasm>, I refer to the approach as "enhanced Socratic method," given that Socratic method was something we all endured in law school.)
The basic flipped-classroom approach — the Thayer Method — was used at West Point for over 150 years for math and engineering courses: Students study textbooks in advance. In class, they work on problems on chalkboards. The professor moves from chalkboard to chalkboard, coaching the students in real time. [1]
(I do basically the same thing with my contract-drafting students: In small groups, the students do drafting exercises using online whiteboards. I lurk on my laptop, quietly coaching in person as needed.)
[0] https://bokcenter.harvard.edu/flipped-classrooms
[1] https://flippedlearning.org/syndicated/avoiding-flipped-lear...
Off-topic and may be found rude - I find multiple instances of "Kahn" in the comments. Is it really that difficult to put in the effort to learn the correct spelling of "Khan" specially when it is everywhere in TFA, the post title, and other comments?
A couple of days ago it was Ghandi instead of Gandhi. I understand it's not a big deal. But it's also not a big deal to get the spelling right.
Considering that WoW came out in 2004 and people STILL sometimes call Rogues "rouges"... doubt it.
This is just the comment section of HN, does the spelling really matter as long as the reader gets it?
Is the article about something else than how math on Khan Academy was thaught?
I remember minimal videos (3-13 min, usually 5-8), and then exercises drilling the techniques until you understand it and don't make mistakes. If you got a perfect score (no mistakes whatsoever), you went a little faster.
That's learning by doing, or am I wrong? Or are there no exercises for things other than math?
I agree with you. It's just an attention bite as nobody would care about this article if it wasn't focused on something as big and popular as Khan Academy. It's clear that the author has never used it as a place to learn something.
Yeah the article feels as though its describing Khan Academy from 10 or more years ago - it is quite odd.
"What he has never had is pedagogical knowledge: an understanding of how people learn, what motivates them, what makes the difference between someone who pushes through difficulty and someone who types “IDK.”"
It is almost as though the author thinks that Khan Academy is an organization of 1, and that they don't employ learning scientists and have a content team and don't publish research papers in the learning science field.
You are wrong in understanding the article.
Khan: Videos + rote exercises
Learning: Projects, complex problem-solving, exploration, argumentation, etc.
Dewey is worth reading.
Direct Instruction - and the largest educational study ever untaken Project Follow Through - would like a work. Project based learning?
Recall practice IS learning. Projects, exploration, and discovery-based "learning" sounds great in theory but in practice, without actual testing, really doesn't live up to the hype.
Adam Boxer is worth reading.
Particularly in early mathematics and language acquisition (but also in most learning domains) you need both rote learning and exploratory learning. Fundamental concepts + exercises to build muscle memory are foundational to enabling students to participate fruitfully in meaningful projects, complex problem-solving, exploration and argumentation.
If you're flailing around without having memorized basic trigonometric identities, you're going to struggle severely to apply them to classical mechanics. If you can't do basic matrix multiplication, you're not going to build a graphics engine.
The article tries to damn Khan with an example about probing how neural myelination works. If you understand the foundations of electricity (by learning about capacitance and impedance) and have done some grueling foundational learning in organic chemistry, ready answers might spring to your mind. You need the former to make asking the latter fruitful or meaningful.
Khan deliberately uses the term "scaffolding" - which since we're throwing around dead education theorists harks from Vygotsky - which is precisely what a teacher provides by pantomiming elementary concepts for a child. Ultimately the child needs to internalize these basics to succeed in more complex projects with a sense of independence.
I really don't understand this article. Two things can be true at once.
Sounds like you should read the article if you have questions about what the article is about?
This article is an example of a rather poor piece of writing. You can't blame people for skimming through it.
I've read the article (except skimming \ fast forwarding 3rd and 2nd paragraph from the end) and it wasn't there. No detailed info explaining why author's criticizing Khan Academy for not doing something it in my experience did. Maybe you haven't read it?
I have been using Khan Academy for over 7 years growing up. It has helped tremendously and taught me to be a critical thinker. There are exercises, quizzes, and unit tests to test a student's understanding and if they get something wrong, KA marks what videos or articles they should go back to and review. I agree with one of the commenters here, this article is uncharitable.
I think there is more to this.
Here's a presentation that, kind of claims the opposite. More specifically, it claims figuring it out on your own is not as good as having a teacher tell you, and then having you use the info, and it claims to be backed up by research
Whenever this topic comes up I feel the urge to point out that not enough people have read Audrey Watter's "Teaching Machines: The History of Personalized Learning", or her blog. We might stop repeating the same mistakes over and over again if we did.
[0] https://direct.mit.edu/books/book/5138/Teaching-MachinesThe-...
My belief is that Khan Academy is tremendously useful when started at a young age and done consistently. I have been doing it for over 7 years and it was a huge portion of my childhood. Long term, consistent use of KA from a young age builds deep procedural fluency and (this is very IMPORTANT:) self-directed discipline that transform how a student handles complex concepts. Even though some critics correctly note and argue that automated drill and practice cannot replace creative, project based discovery and learning, daily mastery based practice eliminates foundational learning gaps (you get a solid understanding), lowers the anxiety around making mistakes (because you get used to repetitive practice), and automates core mechanics (it becomes a basic skill) until they become second nature. I believe that persistent procedural learning is very far from mechanizing education at the expense of real learning. Rather, it frees up valuable cognitive bandwidth and gives the precise structural confidence and fluency required to excel in open ended, high level problem solving that so many critics preach. This is my opinion as someone who did Khan Academy for 7 years (where I learned the procedural step by step learning and practice) and went to school at the same time (where I did the open ended problems and projects). I believe that Khan Academy will help millions of students learn and grow (and the computer programming community is great too!).
I'm curious if maybe the mistake was in assuming we needed AI for the teaching part of the process.
Maybe we should focus only on having AI for the correcting/internalizing part instead? A purely deterministic grader and problem creator creates an endless stream of problems and solutions. The LLM's job is just to help you get to the point that you can assign a random problem from this problem set and the student will be able to answer it without assistance. Hopefully the teachers lecture at the beginning of class helped with understanding as well (I suspect that it would), and also provides a more broad "theory of mind" about what we are doing than the myopic LLM's "Let's get you solving this problem" does. Also, humans are social creatures, and being taught by another human being (even if it were less efficient) is likely beneficial to most people.
tldr; Normal human teacher, deterministic grading to gauge progress, and LLM assistants to help the student get to the point that they can pass the deterministic grading.
The article starts by talking about how interactive learning with Khanmingo failed, and then goes into depth about how watching videos isn’t enough. That’s disappointing. Khanmingo should be superior to passively watching a video because you can interactively dig deeper just like the author says is necessary.
I am responding to the comment, not the article.
The concept of Khanmigo was great. The implementation was basically useless.
It was a great attempt, but the article explains the problem:
"early OpenAI access"
This was literally the world's very first attempt at an agentic tutor, with (initially pre-release) GPT-4. That is worlds away from what's being built with fable or sol-grade models in 2026, or what will be available in 2028.
Why are there people in this comment section who are just downvoting opinions that they don't agree with?
Yeah? That's what the style of teaching is about.
Think less science and more a conversation; establishing syntactic and semantic ground rules for the speakers grasp of a behavior relative to problem.
It's not necessarily about teaching something concrete. It's about teaching a social style in an abstract way. It's discussing a painting or piece of music, in math the symbols used to represent possible number/geometry generators.
I never just watch the videos. I rewrite what is written out. To recreate the song and dance so to speak.
Pragmatically speaking life is just performance art. Only a few specific realms of science move the needle for humanity; biological health maintenance (across all contexts; housing, food, not just medical) and our research in energy infrastructure.
Everything else is just one's relative outcome. Result of their sensory experience. Feels like this should be obvious at this point.
The studies that show brain activity goes down as we use AI. Yeah. So? Is it great to stimulate ourselves so much with ultimately arbitrary content our biology immediately tries to forget due to entropy? Heart attacks are up in <60 crowd relative to last generation. Constant interaction with flame wars and tabs v spaces (functional languages and Nix or gtfo!) computer config wars level inanity is not good Bob.
Comment https://news.ycombinator.com/item?id=49411243 by @dabedee is dead from downvoting but shouldn't be.
Isn’t education often a you-can-lead-a-horse-to-water-but-you-can't-make-it-drink problem?
That article is spot on: we learn by doing and experience, not being told the high level outcomes (which is not without value as a guide).
I can't speak for anything that came later, but in the early videos the majority of the benefit was that the presentation was exceptionally clear, and focused on developing one little piece of a subject at a time, it gently paste format that you could easily pause and rewind over and over.
It was never about replacing exercises, it was there to help you do the exercises from your actual coursework, and to serve as a refresher reference for things you might have already studied but forgot some details about.
Also the videos usually consisted of a while of time spent physically writing out and talking through examples.
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It feels weird and unfair to focus solely on Kahn here when he’s competing with some random teacher or professor’s droning, confusing, non-interactive lecture that’s less engaging and just as lacking in interactivity or application.
I also don’t think he ever purports to be “all you need” to learn.
It reminds me of the people who criticize Duolingo because you can’t actually reach perfect fluency through their app--like wasn’t it always obvious that it was never meant to be the only education you need; wasn’t it always obvious that you need to actually _speak_ a language to learn it? And yet it’s still a great app that has helped millions of people learn languages.
I agree that it is unfair and perhaps even unnecessary to focus solely on Khan here. But I think it must be acknowledged he has caused (intentionally or not) a ton of damage to the state of education. He sparked a movement of “innovation” and “disruption” that managed to push a lot of unproven teaching methods that ran against standard pedagogy which made a lot of entrepreneurs a lot of money.
I don‘t think Khan is solely to blame for this. These entrepreneurs would probably have done equal amount of damage without Khan, siphoning funds away from proven solutions like paying teachers and providing school lunches, and into ballooning administration costs and 3rd-party tech companies. However Khan is for better or for worse the face of this movement and will justly or unjustly get that blame.
Duolingo is however less ambiguous. There is very little language learning going on on their platform. You trick people into playing their stupid game and watching their stupid ads, thinking that they are learning, when in fact they are not.