Salman Khan Isn’t A Fan Of One-Size-Fits-All Lectures

A curious moment from Salman Khan’s interview on The Colbert Report on Thursday:

What we’re seeing in classrooms [with Khan Academy videos] is it’s kind of liberating teachers. So instead of giving one-size-fits-all lectures to a bunch of students – some of them lost, some of them bored – now they can assign this as homework and kids can come into the class and actually do homework there and actually interact and actually take advantage of the fact that there’s actually people in the room there that you can get help from.

Don’t give one-size-fits-all lectures to students. Instead, send them all home with the same ten-minute video.

Someone needs to tighten up that message.

2011 Jun 05: Comments closed.

I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. He / him. More here.


  1. cheesemonkeysf

    June 4, 2011 - 4:48 pm -

    I was also somewhat put off by his suggestion that flipping over to Wikipedia was a sound replacement for historiographic methods and the use of primary sources in teaching the French Revolution.



  2. The really sad thing, is that Colbert didn’t point out the irony of his statement.

    The good news (as a history teacher) is that he checks to references on wikipedia.

    He reminds me of Gilbert Gottfried when he talks. The hand gestures are a little distracting which is probably why he is audio only in his “less boring, less lost lectures.

    I did think Colbert was trying to make a point about him not being trained as a teacher, by saying he should make videos and teach himself how to do it.

    On a very serious note, the premise of it not being necessary to have a relationship with the student, to gain their trust and react to the classroom situation, is a disturbing concept. As Chris Lehmann says, “We teach students, not curriculum.”

  3. Len Bonacci

    June 4, 2011 - 5:07 pm -

    To be fair, I think that what makes it *not* “one size fits all” is that a student can view the lesson at their own pace — they can pause, rewind, etc. In a “one size fits all” teacher lecture, students are far less likely to ask the teacher to stop and go over a point again.

  4. cheesemonkeysf

    June 4, 2011 - 5:19 pm -

    But the whole point of having a methodology for doing and teaching history is that we go to primary sources and read them ourselves, with our own eyes and minds.

    How does going to Wikipedia address that major pedagogical objective?


  5. Then, to tighten the message, he should rephrase to “It’s not a one time fits all.”

    Truth is, all teachers could do this themselves, have a space for questions in the comments, and build the relationship by knowing what the students were not able to understand, regardless of the number of times it was re-played.

    Khan provides an information-dump view of education and knowledge. So there is really nothing innovative about the process. Not saying there is no value, just that it is not great value.

    The best part is that Khan is bilking Gates foundation, and has found a way to make an income by creating sound-bite teaching practices.

  6. For me, I would love to be able to present concepts on video to students outside the classroom. That way, I can make one super polished exact video that covers everything I want and get it in the hands of all students. I miss something every time I do it in person.

    As for the relationship? I argue that this method makes the relationship tighter and stronger. I can do more individually with students. I can more effectively group students in the classroom once I know learning styles and who is stuck where.

    That said, Ric is right. There needs to relationships and that comes with teaching students. I think this comes not from teaching content but really connecting with students and that has nothing to do with content.

  7. In our classes at our school, we have had some success recording lectures in class while we are giving them live and then we post them online to give students an additional option for review, make-up, etc.

    We have also experimented with “flipping the classroom” in some Computer Science classes with mixed results. Some kids love it, some kids hate it. Unfortunately, you can’t really do both with the same section of students.

    What bothers me the most about the Khan Academy discussion you see in the media is that many (mostly non-teachers) view this as a possible replacement for teacher-led instruction instead of a means to augment coursework or as a remediation method.

  8. Time-shifting the lecture is innovating the practice. If the content is essentially identical and static, why not provide solid lectures that present that universal content?

    When I’m handed my room of kids for 50 minutes, I don’t teach the same thing 20 different ways. I teach it one way, and then take questions. So let him teach it the one way in 10 minutes, and let me take more questions.

    How is that not innovative? How does this not lead to more differentiation? How does this not create the time and space for stronger relationships in class?

    I don’t get the controversy. I really don’t.

  9. I’m with you Tim. No one is saying the video is replacing the teacher, this allows for more interaction. And at the college level, large in-class lectures shouldn’t even exist.

  10. Tim and Andy are right. There is no way that you are meeting the needs of every student in your class when you teach the whole group.

    If Khan, or some other video, can present the concept, then I, the teacher, can connect with small groups based on need or learning style and focus on differentiated and specific content needs. Instead of a 30:1 ratio for fifty minutes, I get a 5:1 ratio four five times during fifty minutes. Everyone wins.

    The only problem is that access to devices for watching the videos can be and are scarce.

  11. My grade 4 students find Khan Academy very useful for learning basic math skills. They get as much practice as they need and can move on at their own pace. It’s not a whole math program but a great supplement.

  12. History will not be unkind to Sal Khan, I think. But it will be unkind to the national rhetoric surrounding him.

    His lectures are certainly no worse than a typical high school/college lecture, and are probably better than average.

    But there is really no nuance in the discussion of his contributions to the field. I think that was well illustrated by the Colbert segment.

    Would those advocating serious changes in the ways we teach mathematics really be satisfied with marginally improving the quality of the lectures students receive, while massively improving their temporal accessibility? Probably not. Yet that’s what Khan represents. I have no beef with that, but it’s not the kind of change that will matter seriously in the long run.

    This, I think, was missed by the Colbert segment (and, by the way, we need to remind ourselves NOT to expect serious policy discussion in that venue). When Stephen suggested that Khan’s lectures were unlike any he had seen before, I think he’s dead wrong. Substantively it’s the same thing we’ve all seen (and done) a thousand times over.

  13. A few years ago I started posting videos to Youtube ( using screen capture software, and at the time had no idea who Khan was. Essentially we were after the same thing but I think we found something we weren’t expecting. I thought it would be a great way to get absent students caught up on lessons, and to get students through difficult homework problems. The greatest benefit turned out to be that students were able to pause and rewind me as often as they liked. This removed a huge amount of anxiety from students that might be a bit too timid to ask for help in class.

    However, there are two huge problems with using these videos for more than playing catch-up and remediation: first, if I can create a video that does everything that I do in the classroom, then it’s possible that I’m not as effective a teacher as I would like to be. There should be a lot more give/take between me and the student then a Youtube vid allows for. Besides the relationship building aspect, I think it’s detrimental to the student to not have someone there to guide them through the ideas with probing questions. Second, any school that tries to truly invert any classroom (concept videos at home and investigations at school) and requires students to view videos from home before coming to class is inviting litigation based on access to curriculum.

    I’m not trying to be overly critical of Khan…I think the videos have their place, but not in the way that Khan is suggesting.

  14. The people who teach math and science in the neck of the woods where I live coach football. We have winning football teams but when it comes to math and science our kids are dumb as rocks. You are just not going to make me believe that Khan’s videos are a problem. If this is what you are trying to do, don’t even go there.

  15. In “flipped” instruction, I really don’t see the benefit of assigning a video (whether by Khan or myself or even the best possible lecturer) instead of a reading.

  16. Agree with Tim (10), Andy (11), and Ben (12).

    I don’t see a discrepancy. Maybe he didn’t phrase it right. I think he meant that by “outsourcing” the one-size-fits-all part of the lesson (the video) as pre-class homework, the teacher would then be free to work with each student individually (or in small groups) in class.

  17. Dear everybody arguing that Kahn’s videos are, in fact, innovative:

    At no point have I disputed that.

    What I’m disputing is Kahn’s idea that his videos are anything but one-size-fits-all. And his idea that students who would be “bored and lost” by an in-class lecture will be less bored and less lost when that same lecture is filmed and sent home. If anyone wants to take up either of those points, I’m listening. Otherwise, y’all obviously know where I keep the straw men around here and can carry on.

  18. The videos require a ten minute commitment, not fifty. They can be paused, talked over, you can even chew gum in the same room with them. And they are probably more colorful than the average overhead projector. One-size-fits all? Yes. But for these reasons and others, certainly less boring.

    And that video format matters. I’ve had students say that after they failed to understand me, they went home and watched and re-watched Khan and they got it. They can watch at speed while it makes sense, pause and think or write it out for themselves when it doesn’t. Less lost.

  19. Lots of people love Kahn videos.

    It seems that the vast majority of people who choose to watch them feel like they’ve learned a lot, and many come away with the idea that this is how education should be.

    But they are all biased. They chose to watch. Many of them are adults, who have developed listening skills and mental maturity over the years that allow them to access the material better. Others are motivated students who go out seeking more information. If you *want* to learn, then it is easy! And the Kahn videos will give you a lot of mechanical skills.

    Mechanics are important, and perhaps Kahn’s goal is to free up classroom and teacher time for more theory, exploration, and problem solving. But these videos are nothing new. They’re just a textbook. Now with voiceover. Roughly the same kids who are motivated to learn from the text will be the ones who are motivated to learn from the video.

    So if they are interested, motivated, and smart enough already to think about, go to, and learn from the website, they will succeed at learning how to mimic examples.

    Is this ( ) better than the textbook? Is it better than the teacher doing that problem in the classroom?

  20. Tim (21) does hit the nail on the head of Kahn’s major advantage, however. Control over the lecture is given to the viewer.

    Assuming the viewer arrived at the video.

  21. <i."Roughly the same kids who are motivated to learn from the text will be the ones who are motivated to learn from the video."

    Roughly, but not exactly. My son would far rather read from the textbook than watch a video lecture (me too). Video lectures can be slowed down, but they are damned hard to speed up. If you have decent reading skills and the material is not too challenging, a book is far faster than a video. An in-person lecture, where you can interrupt with questions, is a quite different experience than a recorded lecture. (Of course, a lecture that does not allow interruptions is no better than a video, and could be a lot worse.)

  22. It seems that the vast majority of people who choose to watch them feel like they’ve learned a lot…

    Unfortunately, that feeling is generally a bad sign.

    …they will succeed at learning how to mimic examples.

    That is exactly what they probably learn — no more and no less.

    Again, what is the advantage of a video assignment over a reading assignment from a good book?

  23. I was under the impression that Khan was advocating a flipped classroom, which is not one size fits all.

    True, his videos are, but if the students are told to watch the video for homework, then class time could be spent doing things that aren’t one size fits all.

  24. Joshua Schmidt

    June 4, 2011 - 9:57 pm -

    I think we are dealing with two separate issues – The one that Dan wants to talk about, and the one that we are all dealing with.

    Firstly, Dan. It seems, at least to me, that you want to discuss the concept that Khan said these videos were not in fact “one size fits all”. However, by definition they ARE. Simply put, for these videos to be different “sizes” there would have to be multiple teaching strategies for the same video. If the video was on systems of linear equations, you would need to have substitution method, addition method, and graphing method. Only then would the videos have ANY chance to be anything different than one size fits all (And I’m not even sure my example is any different). While the mainstream media likes to point out that this is a bad concept, I don’t think there is anything wrong with it as initial instruction. Honestly, how possible is it for one teacher in a standard size classroom to be able to differentiate appropriately to every student every single day. Sometimes, one size fits all happens, but you try to improve upon the initial instruction as much as you can.

    Secondly, it seems everyone else wants to talk about the merits on Khan’s or anyone else’s strategy of “flipping” or using video as a supplement to usual standard lecturing. I am not against the philosophy, but is there any student in the world who doesn’t get bored from the same learning strategies every day. I choose to flip my classroom around one a week, along with the multiple other strategies that I use to try and make class exciting as much as I can on a daily basis. If we look this the lens of Khan appropriately, I feel like there is a TON of value in what he’s doing. However, only if appropriately viewed.

  25. @Dan. I’m not going to touch on the bored part but certainly I think than Khans work can help with those who get lost in a lecture.

    A few years ago (before I knew of the Khan academy) I used uTube to present a lesson on division of polynomials. I was able to present three different instructors with three slightly different presentations to the students in half the time it would have taken me. While the videos were playing I was able to watch the students and even before the hands went up I knew who had it and who hadn’t.

    I think Khans videos are horrible in production quality but are fantastic in what they offer the student and the teacher. Fully twice the number of students “got” the lesson than I expected, and another 20% of my class reported that going home that night and being able to replay and pause the lesson enabled them to “get” the lesson. Having the teacher on demand was an incredible tool for those students and so the question of being able to cater to the “lost” student is a no-brainer for me.

    Sure, there are other ways and better ways but video lectures are a start and something that can be done with minimal budget and immediately.

    Having changed methods this year and teaching 9 of the same classes I have begun to make my own videos. Two things about this have really struck home.

    1. I know that I hit all the points that I want to hit each time. Often a lecture becomes fluid and you move off point and miss a point or two.
    2. Students will sit and watch a 5 minute video of me talking to them and doing a presentation but they will NOT sit still for 5 minutes for a live presentation. I am dealing with very young students and 5 minutes is my maximum.

    I believe in personalized learning. If I can set a student a task of watch video A. If you don’t get it then watch video B. I you still don’t get it watch video C. Them come see me. Better yet, pause the video at the point that you don’t get it and ask me to explain that to you.

    I don’t see video as replacing the teacher but I do see it as a tool to free up teaching time and enabling students to work at their own pace.

    I also see it as an incredible supplement to SBG. Have a student who needs to brush up on certain concepts? Assign them particular videos, go over the concepts with them and re-test.

  26. Like many, I’ve made videos for my class. In fact this past year I made individual lesson videos (5-10 minutes in length) for each lesson I taught. The goal was to provide students missing class with a cliff-notes version of the lesson. It was also to inform the parents of my 8th graders what was happening in class.

    It seemed innovative b/c (1) I was the only one doing it in my school, (2) the students hadn’t seen this type of intervention/support before, and (3) I received loads of positive feedback from students but mostly from parents.

    With that said, just because it’s new doesn’t makle it innovative. The SMART boards were novel a few years ago, but they weren’t used for anything other than a novelty. My videos were not innovative. Posting them wasn’t innovative. I can’t say with any certainty that they helped anything. I just hope that I didn’t waste a lot of time making them.

    Our school is going to pilot dozens of ‘smart’ classrooms, but even as a receiver of one of these classrooms, I’m struggling to determine how the addition of permanently installed hardware is going to make anything better.

    Maybe I’ll just play videos of myself teaching my students in class as an warm-up, ask for questions, then assign homework to be done in class.

    That’s an approach that my students haven’t seen. Is that innovative?

  27. Rick Lehman

    June 5, 2011 - 5:11 am -

    I assigns videos for students to watch at home. I create these videos myself and they are typically 5-10 minutes long.

    I do not believe my videos are “one-size fits all”. Although, my method is slightly different than Khan’s. My initial video is fast, and explains all the objectives that students need to accomplish. Then students take an online formative assessment graded by Google Forms. They are sent a link to corrective videos for any problems they missed on the formative assessment. This way student receive additional instruction in the concepts they have misunderstandings. It takes a long time to set up this type of system, so much prep. Although, once it is set up, it runs on auto-pilot and a teacher can focus on intervention, enrichment, and facilitation of learning.

    As for the claim that the videos would still be just as “boring” as the in-class lecture. Guys, please stop arguing with Dan on this point. No amount of animation, color, or multimedia can really make up for the teaching methods/style a teacher uses. If you are a boring teacher in class, you will be a boring teacher in video. Switching to video will not solve this problem. I believe Khan is trying to say that by using Khan Academy videos my students will be less bored. hmmm… Shouldn’t I take offense to this, or at least as a reflection of Khan’s opinion of my teaching ability? In my opinion, Khan’s videos are not that engaging, and his older videos are downright terrible quality.

    I am teaching Summer School Remediation starting next week. I will be using Khan Academy for this 3 week remediation period. I believe remediation is the current best use of Khan Academy, due to it’s practice system being able to determine the current lesson a student needs to focus on and scaffold there learning from there.

  28. Also, I think it’s important to remember other benefactors: those without access to good books or regular education. As the internet becomes cheaper and more ubiquitous, sites like this will help bridge the gap between the global rich and the global poor.

    Is a real teacher better? Certainly. Is a real teacher necessary? Not really, nor is a dozen expensive books. It is conceivable that within this decade rich and complete curriculum to get you from addition through calculus will exist online for free (and in other languages – Khan is working on this too). That’s not ideal, but it’s awesome.

    The self-pacing possibilities excite me. With a bit more time, math class could become something each student takes at their own pace. Students who would be bored in class could go at twice the clip and get through Calculus by ninth grade – why not? In public school classrooms which so often go slower and slower for standardized testing, that could keep some great math minds in the game longer.

  29. I’m unimpressed by Khan and his videos. If I want to watch provocative video mini-talks on mathematics (and I do), I go to Jim Tanton’s YouTube offerings. The differences are obvious. Jim’s a mathematician. Jim’s an outstanding teacher with a background working with Robert & Ellen Kaplan’s Math Circles group. Many of his videos leave the viewer with more questions to think about than answers to accept. In a nutshell, Tanton is doing real, quality teaching, not the business-as-usual gruel Khan serves up.

  30. I ask a third time: In what way is it better to assign a video lecture before class instead of a reading from a good textbook? Is it just a matter of catering to illiteracy?

    I think it’s important to remember other benefactors: those without access to good books or regular education.

    It is a simple matter to make a free textbook available on the web; a great many math teachers have done so already. Also, a downloadable 1MB PDF file is a lot more generally accessible than a year’s worth of web videos.

  31. Many years before Khan started with lectures, people began putting up interactive websites free of charge for anyone to use to really learn math and science concepts. The real revolutionary and unsung hero was Walter Fendt.
    I believe Colbert’s responses are pretty sarcastic about lectures. Maybe you are missing the sarcasm. Remember pseudoteaching? What about the MIT lectures? Go to mathwarehouse or analyzemath or bbc or mathsnet. If you want a free book, go to purplemath or regents prep.
    I used to be upset when I heard what rubbish students were being told, but then my daughter (a teenager at the time) said, “don’t worry, mom, they’re not listening anyway.”
    A cheap version of homemade Khan is to have a student use a smartpen ($50) as they go through a problem. The question and answer voices are recorded along with the writing, so you can ask the student what s/he doing and why, and then you can post it on-line. Student-led, not illegal because the student is not identified, and they’d much rather listen to a classmate than to the teacher. It’s not nearly as effective as the interactive learning offered in the sites above, though

  32. We need to distinguish here between _use of video_ and _Khan’s use of video_.

    Dan’s own stellar work in connecting storytelling, video, and lesson delivery makes it very clear that his criticism of Khan is not that Khan uses video to deliver content, but that the production of Khan’s video itself stinks (not to put too fine a point on it). Or, put more gently, that Khan’s particular use of video as a medium does not add value in and of itself to the lesson.

    (A web-based PDF cloze worksheet is still as ineffective at teaching persuasive writing as a photocopy on a desk. It’s the same damn worksheet.)

    Proponents of video will argue here that it is the rewind/review/pause/time manipulation benefit of video that is the value-added factor and overrides the quality of the content itself, particularly for remediation purposes. But I would argue that this largely is a symptom of how inefficient learning becomes with poor content. If I have to review, rewind, pause, and otherwise slog my way through a video of poor content delivery, well, super. I’m taking an hour to teach myself the stuff that good content would be able to do in ten minutes. Never mind the demonstrable affective factors involved in the slow slimy slide towards hating math, or English, when a student has to *work too hard.*

    But let’s say for argument’s sake that Khan was also a master of video– or even, more accessibly for most of us, a brilliant teacher who simply filmed a lecture to go home. Dan’s second inferential point is that video, no matter how brilliant, is always a static product. It is to be consumed; it does not respond. (Not yet, anyway.) It can’t identify Mack’s knitted eyebrows or Melanie’s near-tears, walk over to them, and say, “You look confused, friends. What’s stumping you?”

  33. Although I don’t like the way Khan is glorified, he does have some good lessons. The algebra lesson someone pointed to earlier is a very nice intro.

    His lectures don’t go deep, but some of my (college) students love being able to watch them. Watching video works very differently from reading textbooks, and many of my students who do not believe they can read a textbook are quite comfortable listening to the same thing on a video. And getting to pause it, replay it, and think about it while on their own is very empowering for them.

    I love Tanton, but many of my students prefer Khan. Maybe it’s a first baby step forward, but for them it’s something.

    As I look for ways to help my students develop a more positive relationship with mathematics, Khan is one of the many novelties I introduce them to, hoping to help them find something that works for them individually.

  34. I just deleted a few comments. Play nice.

    There are a couple of really great points I’d like to engage later from Tim, Scott, Joshua, and Dina. For now, I’ll commend them to your attention. (If someone wants to take up R. Wright’s question about video v. text, also, I’d be obliged.)

    For the record, this is the absolute softest critique I could possibly level at Sal Khan: that he misunderstands his own work. I haven’t even commented on the work itself – what I appreciate about it, what I don’t like about it – or on the meta-level national discussion (funded by Gates) about where his work could be put to good use.

    I’m not sure I’m ready to moderate that comments thread.

  35. This gets away from one-size-fits-all by freeing up teacher time to work one-on-one with students.

    My goal for my grade 9 course next year is to have every content lesson available as a video lecture(probably a link to Khan’s work), textbook reading and discovery process, then allow students to choose which way(s) they want to be introduced to the content. I’d like to add online homework questions so that students can do as many as they’d like, or as few.

    The extra class time that gives me is time I can spend one-on-one and working on higher order skills rather than content.

  36. I think one-size-fits-all is a problematic phrase. His is a one-form-of-explanation fits all, but the format implies one-pace-doesn’t-fit-all.

  37. Like many here, I’d never want to take the live teacher out of the equation (if there’s a pun there, please excuse it). However, I do think what Khan does can be improved with a web-based interaction between students and teachers. I’ve been using a message board on my web site,, so students can view presentation videos and respond to each other or to me only on our message board.

    Although I like the face-to-face interaction with students, this sort of online marriage of media is very effective for teaching and learning.

  38. I agree with Len Bonacci (comment #4) in that the way a student listens to a talk can differ and that is the advantage. However, Khan says “actually do homework there and actually interact and actually take advantage of the fact that there’s actually people in the room there that you can get help from.” I don’t agree with the fact that the same flexibility isn’t needed there as well. Some students know how to solve equations within a couple of exercises. They don’t need more time in class, so why keep them boxed in between four walls. Other students, however, need more help and then one teacher in one hour often is not enough, apart from the fact that they encounter similar misconceptions and problems. So, in striving for more flexibility in math classes, I think Khan bets too much on one horse. It is not a question of technology but of allowing teachers and students alike more flexibility. Here, technology could play a role.

  39. Watching video works very differently from reading textbooks…

    Could you elaborate on that?

    …and many of my students who do not believe they can read a textbook…

    I know that there are many, many math textbooks (perhaps the majority) that are nearly unreadable, but I think that if a student really cannot read any math textbook at the level of the course in which (s)he is enrolled, that student is enrolled in the wrong course (or has deeper literacy issues that should be addressed before beginning that course). But I understand that, as a college teacher, it is somewhat my “luxury” to see things that way.

    …are quite comfortable listening to the same thing on a video.

    To be honest, it makes me very nervous when student intellectual comfort is put forth as a positive condition in mathematics eduction (or education in general, I suppose). A while back on my blog, Christopher Danielson kindly pointed me to an eye-opening video discussing this issue, coincidentally also in the context of Khan’s physics videos.

  40. I am just reading a paper by the math educator Paul Cobb, who states that an environment for learning mathematics should incorporate the following qualities:

    1.) Learning should be an interactive as well as a constructive activity – that is to say, there should always be ample opportunity for creative discussion, in which each learner has a genuine voice;

    2.) Presentation and discussion of conflicting points of view should be encouraged;

    3.) Reconstructions and verbalization of mathematical ideas and solutions should be commonplace;

    4.) Students and teachers should learn to distance themselves from ongoing activities in order to understand alternative interpretations or solutions;

    5.) The need to work towards consensus in which various mathematical ideas are coordinated is recognized.

    I think what is of importance in conversation around teaching mathematics, lecture, text-based, video, etc., is the notion of authority: authority of knowledge, author-ity of knowledge, and authority for knowing. Each of these speak to the learner’s position of him/herself within the world, maybe called his/her (mathematical) identity.

    I suggest that when education gets treated as “reception of knowledge” all (?) that is important in the role of the teacher and of schools can be discounted. It is the present (and previous — see 1930’s for example) danger of the economizing of education.

    Cobb, P. (1990). Multiple Perspectives. In L. P. Steffe & T. Wood (Eds.), Transforming children’s mathematics education: International Perspectives (pp. 200-215). Hillsdale, NJ: Lawrence Erlbaum.

  41. R. Wright, where’s your blog? I’d like to follow it. (I blog at Math Mama Writes.)

    >To be honest, it makes me very nervous when student intellectual comfort is put forth as a positive condition in mathematics eduction (or education in general, I suppose).

    I hear what you’re saying, and I make myself nervous sometimes. But the first step has to be pulling them in. After I have some commitment on their part to really put some intellectual effort in, then I can push them to think harder.

    The video helps them take that first step.

    Maybe your college and mine are different sorts of students? I teach at a community college where the majority of the students have grown up dealing with poverty.

    I’ll try to come back to the video vs textbook question later, though I don’t think I have anything deep to say about it. I’m out for the summer, or I’d ask my students your question.

  42. Joshua Schmidt

    June 5, 2011 - 12:51 pm -

    I just want to throw my opinion in the hat that flipping the classroom is innovative in many ways and something that I really enjoy. However, the video that you use to flip the classroom DOES NOT change between the one size fits all instruction that we are viewing. You are differentiating the learning structure for each student, but it’s about the ability to free up class time, not the video itself. I love making videos as much as anybody else, and I get very positive feedback, but I worry that we are making them out to be something they aren’t.

  43. One thing I love about Tanton’s videos is that, like his books – both the THINKING MATH series and the SOLVE THIS! book, they frequently raise more questions than they answer, and he rarely concludes, “Okay, that’s the way it is.” He almost always gives students choices about how they want to think about mathematics: if you want to think THIS way, then you’ll probably agree with X, but you have a choice.

    Also, he tends to look at a lot of WHY? questions. And of course, that can be intellectually more painful than many students are looking to deal with. Anyone who has taught math likely knows that we’ve trained students in this country not to want to grapple with the whys, only the hows (if anything at all). “Just show/tell me how to do it. Just tell me the answer.”

    Tanton is far too much of a mathematician AND far too much of a teacher to settle for that, but I think he is excellent (see SOLVE THIS!) at posing problems that have layers of understanding/complexity built in, and he likes to give hints, not fully-fleshed out maps of “the” solution, and then often extensions/generalizations of problems.

    I strongly urge people to visit his site,, download the free pdfs., check his videos, look for SOLVE THIS! (which my local library actually has), and definitely subscribe to his monthly newsletter (which will be on hiatus until September, I think). He poses some beautiful problems and challenges there.

  44. I have a bad habit of numbering my points on the internet. Anyway:

    (1) The most charitable read I can give those comments by Sal Khan is that while his videos are still “one-size-fits-all,” a teacher using his videos can make the class room less “one-size-fits-all.” How? Before, a teacher was giving an explanation in class that 20% (or something) of students understood on the first try. Then 40% more students will get it on the second shot, but the first fifth are bored. Then 20% of the class will ask questions (majority of class is bored) and 20% go home confused. Now, I take it that the idea is that with Khan’s videos you can get the first few passes at home, so that 60-80% understand the material coming into class. The teacher can allow students who understood the lesson the night before to practice, and the teacher can focus in on the rest. Differentiation is easier, so the educational picture as a whole is less “one-size-fits-all” and less boring, even though the lecture is just as “one-size-fits-all” and just as boring as a human being lecturing. I think that this, at least, makes sense of what Khan was saying. I don’t think he was saying that his lectures are more engaging, or whatever.

    (2) That having been said: there’s much to be worried about in this picture. As others have mentioned, there’s really no reason why the above can’t occur with a textbook, or an interactive website. That raises two related questions: what is innovative about video, and why hasn’t everyone been working on this more personal, more engaging, less boring learning structure with texts or interactive websites?

    (3) If I assigned large chunks of nightly reading to my students, they wouldn’t do a great job with it. Most of them would read thinly, skimming over parts that they didn’t understand, and then quickly moving to the worked examples so they could duplicate them on the homework (or whatever). Then, in class, I would have a difficult scenario: half a class lost, half a class smugly assuming that they know everything that I’m going to say.

    There has to be a way to teach my high school students the proper way to read a technical text, and I very much want to work on this next year. (Suggestions Appreciated!) But there’s a reason why I still reserve for myself the first pass on any new topic or idea. I want to frame it for them, highlight the difficulties, and show them what is exciting and interesting about it.

    And how are videos different from textbooks? I should probably shut up and let psychologists and folks who actually have researched this stuff opine, but my own experience with videos leads me to believe that they’re focus-optional. If you’re being honest with yourself, you can’t “read” a chapter of a book without focusing, since the act of reading involves understanding each successive sentence. A video, on the other hand, is going to finish whether you understood it or not. I think it’s easier to fool yourself with a video. But it’s also easier to complete and requires less focus, which is why (I think) some of my students like it. In a word: laziness.

    (4) I’ve learned most of my math since high school from reading textbooks, and I don’t think that you NEED to have a human being present for learning to happen. Otherwise, why the heck am I lugging all these books back and forth from the library. At the same time, most of my high school students aren’t able to read a text honestly enough to gain from it. And if Bill Gates is looking for a way to help us minimize lecturing in the classroom, I’d prefer he help me learn how to teach kids to read these books rather than working on videos.

    (5) Now, one last complaint: I don’t think that Sal Khan is very good at explaining math. First, because his tone is constantly reassuring. “This isn’t so hard” or “But we know how to do this” are the wrong sorts of things to be telling kids. That sends the message that real effort isn’t needed to grasp this content. The sort of things I prefer to say in the classroom are “This is hard–let’s think about it for a minute” or “This is a big, new idea.”

    Second, I just don’t think he does a great job providing context or motivation for algebraic procedures. Here’s a quote from his lecture on systems of linear equations:

    What we want to do is eliminate a variable because if we can eliminate a variable we can just solve for the one that’s left over. The way to do that is, let’s say I want to eliminate, I feel like eliminating this y. I think you’ll get an intuition for how we can that later on. The way that I’m going to do that is make it so that when I add this to this they cancel out. Well, they don’t cancel out right now, and so I have to multiply this bottom equation by 4, and I think it’ll be obvious why I’m doing it.

    Things are up to his feelings, they’re obvious, you’ll get it, don’t worry. Anyone in a classroom knows the sorts of questions that this explanation will yield: “Why can you just multiply it like that?” or “How can you just eliminate the y’s?” His explanation just skips the hard parts. He buys his clarity to students on the cheap, by just focusing on the easy parts.

    Finally, with all the funding why can’t they have lecture videos that are easier to navigate? My kids just can’t find the right ones. I would have the site remember your state, and then present you with the lectures aligned with the particular state’s standards and sequences. I’d also have the videos organized topically in some way, so that all the “systems of equations” videos are grouped together in a more logical way.

  45. Love what MBP says about Khan’s language. It’s evident that, although he means well, he’s not a teacher. Your suggested language, “This is hard — let’s think about it for a minute . . .” is a much better way to get kids thinking and working.

    Plus, they’ll feel as though they’ve accomplished something if it’s a “big, new idea” rather than something easy, which may also mean unrewarding.

  46. A very debatable issue, given its 44 comments in only a day. Dan, I’d like to touch on the two points you’re making.

    First, I think Khan uses what’s happening in far too many classrooms as his reference point when he says his videos are anything but one-size-fits-all. I’d imagine that he sees a “traditional” classroom as 55 minutes, 10 of which are warm-up and going over HW problems, 30-35 of which are lecture, and 10-15 of which are practice problems. That one size, as we know, does not fit all, and his alternative does fit more. A 10 minute instructional video can take 10 minutes for the students who get it and are ready to come into class to practice some more challenging problems. It can take 15 minutes for the kids who want/need to watch it twice, and maybe have some questions on particular parts/problems in the video. Or it can take 20-25 for the kids who need to see and hear things three or four times until it sinks in. Right there is three different learners (and I think we all know we have more than three different kinds of learners in our classrooms) finding a more customizable experience.

    And second, kids will be less bored at home. It’s not the same lecture. It’s a 10-minute version of a 30 minute lecture, a lecture that takes 30 minutes because the teacher sees that three students are lost so he remediates on the fly and takes 2 minutes because someone called his classroom looking for so-and-so and takes 5 minutes to answer two questions while trying to engage the student who understood the concept 5 minutes before that. And they’re less bored because they’re checking the text that just came in while pausing the video while toggling to the window that has Facebook open. I’m not saying this is the best learning environment, but I’m sure they’re less bored.

    I haven’t talked with Salman Khan, but those are my interpretations of the points he’s trying to make. I wouldn’t go so far as to say that his idea of a flipped classroom is an ideal learning situation. I did, however, before I knew who he was, send my kids home over winter break with video lessons and practice problems. They were then able to email me and submit their work or ask questions. It was a wonderful way for me to squeeze in two extra lessons over a two-week period when my students would have normally been completely detached from school-work.

    As Jay-Z says, just my thoughts…

  47. I suspect Dan’s issue is not with the production quality, but that it’s a video version of everything textbooks manage to screw up.

    I find it disheartening that it is often taken for granted that this is the only, much less the most effective, method to teach anything.

  48. Mr. K: I find it disheartening that it is often taken for granted that this is the only, much less the most effective, method to teach anything.

    No joke. The goalposts on this debate are unbelievable. On one side of the field, video lectures. On the other side, teacher lectures. The commenters in this thread, by and large, are eager to compete for the territory between those two goalposts.

    Except in the case of rank incompetence (where the teacher-of-record couldn’t possibly compete with a video lecture) we are playing on the wrong field.

  49. I don’t think we are playing opposite sides. I think we are saying we are playing in the same goal. I don’t really want to argue whether one lecture is “better” than another, as clearly I’m not the best math lecturer in the world (if the reader is, let’s get your videos up then, the rest of us can rest our voices), I mean to argue that an on-line person is no improvement over an in-person-person.
    This year our students were subjected to “blended learning” which required teachers to use only prescribed inquiry lessons, with information supplied only from an on-line textbook and lecture videos such as Khan Academy. This work was done in school. Since our kids did not get textbooks, the on-line material was all they had.
    I’m glad for those educators who have students that peruse these math sites from home – ours don’t. Nor do we get to pick which class the students are placed into – clearly nobody in their right mind would put students who cannot add and subtract into Algebra, but the placement people are not in their right minds.
    We have one benefit going in to next year, when students will be given books and in-class real experiences – most of the students recognize that the learning experience they got this year was not very meaningful (polite phraseology). It is possible that they will have more enthusiasm for the in-person classes next year, but again, if all I do is lecture, what’s the point?
    I liked “If there was a right way to teach math, we would have found it by now.”(T. Sallee, your site)
    When administrators ask what I’m going to do to have kids learn all math since 1st grade in the next 3 months, I always ask if they know what to do. I assure them that if I knew how to fix it, I would. Since they apparently know, I need them to share with me. I’m still waiting…
    But WCYDWT does get my students thinking, and interacting. The mall has complained that kids are running up the paired escalators and timing each other. I am saving up bathroom tissue rolls in various stages of use, so we can figure out when the custodian should change the roll so that we don’t run out any more… they may not be able to do the math, but at least they’re interested (step 1).

  50. cheesemonkeysf

    June 5, 2011 - 4:11 pm -

    Where is the actual evidence of effectiveness?

    That is my question.

    There are clearly a lot of YouTube views and personal/incidental anecdotes out there. But as a 21st-century-educated citizen trying to make the best possible use of our scarce educational dollars, I want to know *ahead* of implementation that there are data to support (a) the conclusions which are being drawn and (b) the methodologies that are being promoted.

    So please just show me the peer-reviewed data demonstrating that KA is more effective than any of the scientifically validated, evidence-based math or science pedagogies we math and science educators work with.

    If it is indeed practical and effective, I have no doubt that — like other well-thought-out pedagogies — it will stand up to rigorous scrutiny and analysis.

  51. Alex Eckert

    June 5, 2011 - 4:26 pm -

    Re: The commenters in this thread, by and large, are eager to compete for the territory between those two goalposts.

    That’s because it’s the topic at hand. Propose the question of if Khan’s flipped classroom/degree of boredom/many-sizes-fit-many philosophy is the answer and I think you’d see plenty of people competing for territory on an entirely different field.

  52. Maybe I am old fashioned, but I just don’t get this trend. The motivated student seeks help. On video, in person, via email, and Collaborize. I give mathematics a human quality. A big picture, questions bring meta-cognition to a subject. How does one ask a video a question? I don’t get how what Khan is doing is different than what I can offer, except that it can be rewound and paused (and it is available 24/7) Don’t get me wrong, I think this is a fabulous community service for those willing to seek it…it is the undermotivated, the ones who can’t get it one way, the ELL learners, I don’t see my 3rd year Algebra 1 students bringing more to the table after watching the video…I’ve offered! Please use youtube, purple math, Khan Academy…students need to learn accountability first, critical thinking next, and then maybe a Khan video will make sense…


  53. @R Wright and MBP re: How is watching a video different from reading a textbook?

    Gas Station Without Pumps says it’s slower. Sue Van Hattum say it’s less intimidating. The only addition I can make is that my students are familiar with watching videos about things they don’t know (Myth Busters, How Things Are Made). They’re not familiar with reading text about topics they don’t know, having apparently never been taught how to do it.

    It’s helpful to be able to pause, rewind, ask questions, make inferences, take note of problems you want to try to solve. Students who do well in my class use these techniques on their textbooks. Students who do poorly don’t realize it’s even possible, let alone helpful. Maybe there should be “pause” and “rewind” buttons printed at the bottom of the page. Heck, my best students use those techniques on me.

    MBP, I think you’re mistaken in your statement that videos are focus-optional while books are not. It is absolutely possible to scan your eyes across the page and make word-noises in your head without focusing on the meaning of the words. It’s what my students mostly do. I’ve just begun experimenting with teaching “technical reading” — I’d love to talk more about this with anyone who’s interested (my blog is linked under my name, above).

    The best resources I’ve found on helping someone learn technical reading: Mortimer Adler’s book _How To Read A Book_, and Cris Tovani’s _Do I Really Have To Teach Reading?_

    Yes, I sometimes screencast. It has its pros and cons. Ultimately, the skills I want for my students aren’t the ones Sal Khan teaches. They’re the ones Sal Khan has.

  54. Cheryl van Tilburg

    June 5, 2011 - 5:37 pm -

    I can’t tell you how sad Dan’s sarcastic comment at the end of his post and the negative comments about Khan and his videos look to someone who’s not a math educator — but is still an educator (HS English lit) and the parent of a struggling math student. Why so much underlying bitterness?

    The guy’s not perfect, but what he’s trying to do — at no cost to anyone reading this blog — is fantastic. I currently live in SE Asia, and for kids in poor countries here, who often don’t have access to a great math teacher like one of you, these videos represent a potential sea change. There’s an Internet kiosk in every village. Can you imagine the impact? And for my own children, who often sit through 83-minute math classes too embarrassed to ask a question, Khan’s videos represent salvation — or at least enough of an explanation to give them the confidence to raise their hand or give the homework a try.

    Dan, I’ve been reading your blog since you started (I think Jose Vilson pointed me here many moons ago), and what you do with math instruction is amazing. I wish my kids had you (or one of your blog commenters) for a teacher. But please think about the affects of tearing someone like Khan down. He’s doing his best. He’s not charging for it. His efforts could have a positive impact on children who could really use the help. Maybe instead, you could offer to help him make his work better…. Can you imagine a Dy/Dan-Khan partnership? Now that would be cool.

    So before you rip Khan a new one, I’d ask that you consider if what he’s doing might have any value that could serve

  55. I don’t know what all the Kahn bashing is about. I don’t think he sees himself as a replacement for teachers, but as a supplement.

    I tutor college math, and I recommended this to my students all the time. I have gotten only positive feedback.

    Free math help for anyone? Thank you Kahn.

  56. I did a version of the “flipped-classroom” using books back in 1998 and 2003. The idea was simple: I did not lecture, only answered questions about the homework and worked problems live–the students had to read the book and work on the homework before coming to class.

    I blogged about it a year ago:

    The results were mixed–it worked very well when I did it with a class that opted to be in a section that had that organization, but not so well with a class that had it forced on them.

  57. a different Josh Schmidt

    June 5, 2011 - 7:03 pm -

    For me the dichotomy isn’t between teacher lectures vs. video lectures or between individualized teaching vs. “one-size fits all teaching” but between classroom learning time and home learning time.

    Classroom time is hopefully making full use of the ability of the students and teacher to enter into a conversation, ask questions and explore. When done well the teacher can motivate, instruct and remediate in a highly flexible fashion and tailor the lesson to best meet the needs of the unique situation in front of them.

    The question is what happens when the students go home? What is the best use of their time when they *don’t* have access to a teacher (and yes there are some steps towards interactive web sites and the like and perhaps these are the answer, but the *teacher*, the one who best understands the unique student, is not available at home regardless). Dan’s WCYDWT problems strike me as excellent uses of class time, but seem problematic at home. I can think of four typical answers to this question of what to do when the student is at home: 1) do nothing (assign no homework) 2) assign textbook reading 3) assign practice problems 4) assign a video lecture.

    Of course combinations are possible and I make no claim as to being exhaustive.

    Assigning no homework appears to many to be an inefficient potential waste of learning time. With an effective answer to the homework question, students could probably learn more.

    Textbook reading is often problematic at the high school level. Students can and do move their eyes over the page, finish the reading just to “get it done”, and retain little. But this works very well for students who learn from books easily.

    Video lectures seem like they would have many of the same problems as textbook reading, but since many human beings are good audio learners, perhaps a greater percentage of the students could retain information.

    Practice problems have the difficulty that students who already know how to do the problems learn little and students who are stumped also learn little. Leaving a small percentage of students who benefit from a little bit of polish to their skills.

    Video lectures do seem like a useful tool to address “home learning time” problem, and I suspect that is where a lot of their feeling of “innovation” is coming from. But the home learning problem remains to me and I would greatly welcome anyone’s suggestion as to how best use a students home learning time.