Lectures Are a Small Part of Learning

FriendFeed and Twitter are a terrific source of articles about how New Media technologies are Changing Everything. The latest example is Sebastian Paquet’s The Fate of the Incompetent Teacher in the YouTube Era, in which he declares that the recorded lectures of Salman Khan are the beginning of the end for bad teachers:

Even assuming, conservatively, that Khan’s calculus videos are only slightly above average, roughly half the students taking calculus this semester would save time and pain by watching his lessons instead of paying attention to the mediocre teaching happening in front of them.

And I’m not talking about students who don’t have a teacher, or eager minds who are stuck in a class below their ability level. The latent demand for this kind of stuff is huge.

“But these are just videos, not a real flesh-and-blood person you can interact with!” True. But I maintain that a great video compares favorably with a live, but bad, teacher in a classroom setting. You can’t interact productively with a bad teacher anyway.

I’m less convinced. Nothing against Khan– I haven’t watched any of his lectures, to be honest– but this isn’t really anything new. Students have always had access to better explanations than are provided by bad teachers– they’re called “textbooks.”

The parallel isn’t exact– reading and listening are different learning styles, etc.– but the basic structure is similar. You have teachers who are inexperienced or just plain bad, but the students have access to a quality explanation written by experienced teachers and tested by use in tons of classrooms. So, why do we still have teachers, when students can simply learn from textbooks?

Because while there are plenty of examples of autodidacts who teach themselves some subject simply by reading books on the subject, for most people, the explanation is only a small part of the process of learning. Whether it takes the form of a lecture or a textbook, the “this is how it works” explanation is only the first small step. The really essential part of the educational process comes when students try to apply what’s been explained to new problems. Even a very good lecture just gives you the outline of the subject. To really understand something, you need to apply it.

That’s always the hard part. There are lots of very good books out there, most of them explaining their subjects significantly better than the average lecturer. We haven’t abolished classes in favor of self-directed textbook reading, though, because lecture isn’t where the heavy lifting is done. Most students learn more from taking courses than from reading on their own, because students taking a class are forced to do homework, while most students reading textbooks on their own don’t do the problems. This is even true of students “stuck in a class below their ability level.” I might go so far as to say that it’s especially true of those students– I haven’t been teaching all that long, but I’ve given a goodly number of B’s to students who felt the class was beneath them.

The vast majority of the students who say they aren’t learning because of incompetent teaching are lying. Mostly to themselves, but certainly to whoever they’re complaining to. I’ve been on both sides of the classroom, now, and looking back on my own education, I have to admit, I’ve done the same thing. Most of the times when I complained about the quality of the teaching, and blamed the professor for my failure to learn a subject well, the real blame fell on me– I was not putting in the necessary effort. More inspiring lectures might’ve created the illusion of greater understanding, but without putting in time and effort outside of class, the end result would’ve been no different.

So, while Sebastian waxes rhapsodic about the Shiny YouTube future, including gems like:

Some of the poor teachers will look so bad that their students will simply laugh and walk out if they can, or tune out if they can’t. They will only show up in class to get evaluated.

I am highly skeptical that this model will ever pan out. YouTube lectures may very well provide a useful supplement to some classes, but at the end of the day, lectures are a small part of the learning process. The number of students who will actually learn a subject primarily by watching video on the Internet is pretty small.


  1. #1 katydid13
    October 27, 2009

    In the late 1980s-early 1990s, my high school had very large old televisions everywhere and several large classrooms fitted with multiple tvs. These were the remains of a 1970s era experiment where they were going to have the best teachers lectures and onsite teachers would handle all the other stuff. Apparently, this lasted about one school year.

    I don’t think this is a new idea. Online classes work because of the ability to interact. I don’t think there is any substitute for that for most people not brilliant enough to teach themselves anything.

  2. #2 Seb
    October 27, 2009

    Thanks for the link!

    I agree that access to good explanation helps, but is not at all sufficient for learning.

    My argument was that, all things being equal, the typical student is better off tuning out of class entirely and spend the time watching a good explanation video than listening to a bad teacher.

    Of course, if he isn’t the auditory learner type he can also tune out of class and use the time to do things like read textbooks or do problems, so I guess my argument only really applies to people who learn well when listening to lectures.

    What do you think?

  3. #3 Brian
    October 27, 2009

    The flip side to this is that teachers themselves have a huge resource of other teachers to watch and compare themselves to (and steal ideas from).

  4. #4 John Novak
    October 27, 2009

    You’re missing a key element of why the traditional teaching model is still so strong: Accreditation.

    The relative merits of learning via live lecture, vs learning by recorded lecture, vs learning by adaptive digital lecture and drill, vs whatever do not matter as long as one of them comes with accreditation and prestige and the others do not.

  5. #5 Lethe
    October 27, 2009

    Someone who is a bad teacher can completely scuttle student learning, not by being a bad lecturer, but by teaching the wrong topics or the wrong way of thinking about them. The student might not even realize that they didn’t learn anything useful until the real world points it out.

    An example: A close friend of mine took a graduate-level chemistry class in spectroscopy, and watched the teacher spend most of a month on term symbols, and another few weeks on atomic spectroscopy. These are worthy subjects, to be sure, but that left only a couple of weeks for the actual spectroscopy of molecules, which is what she (and basically every other student in the class) needed for their research. When I took the same class a few years before, it was taught by a different (and vastly more skilled and interested) professor who spent the majority of the semester on the sorts of things that the students would actually be likely to encounter. This made my road through grad school a whole lot easier than hers.

    Oh, and the same bad professor above, when teaching the only analytical chemistry class that many of the students would ever see, decided to skip teaching chromatography because he didn’t find it interesting. Never mind that many of the non-grad school bound students would spend the rest of careers parked in front of chromatographs…

  6. #6 evan@goer.org
    October 27, 2009

    To follow on to what John said — MIT’s Open Courseware has some amazing stuff online. Videos! Lecture notes! Assignments and exams with answers! And it’s all free.

    MIT is happy to do this because they know their real power resides in the 4-year-college as a rite of passage. It’s not the lectures or the coursework per se, it’s about conferring accreditation, prestige, and social class. That’s the thing that’s (apparently) worth $200,000.

  7. #7 Chad Orzel
    October 27, 2009

    Accreditation isn’t just a conspiracy to keep autodidacts down, though. The institutional accreditation amounts to saying “We assert that this person has demonstrated mastery of this material to our satisfaction.” It’s a certification that the person has done the work and taken the tests– a guarantee that the student in question has done something more than just watch the lectures.

    You could perfectly well replace that with a system of professional entrance exams, or some such, and use the institutional prestige of the testing organization as your guarantee. In which case, I would be perfectly happy to let self-taught students watch video lectures for free and then take the exam (provided there is some fee for the test to discourage completely frivolous attempts), in the same way that we allow students to test out of intro mechanics based on their scores on the AP exam.

  8. #8 John Novak
    October 27, 2009

    I didn’t say it’s a conspiracy. It’s just a fact. Professionally, it does not matter how you got the accreditation. It only matters that you got it.

  9. #9 Eric Lund
    October 27, 2009

    Accreditation isn’t just a conspiracy to keep autodidacts down, though.

    Completely in agreement. There are a number of places out there that claim to be institutions of higher learning but don’t actually teach their students anything useful. This category includes certain religious schools* (most infamously Liberty University) as well as schools whose administrations seem to have majored in nocturnal aviation. Since there are a few thousand legitimately accredited colleges and universities in the US, there has to be a way to distinguish one of the lesser known schools of this type from the diploma mills and religious indoctrination schools.

    *I realize that some religious schools are fully accredited, but others never went to the trouble.

  10. #10 ScentOfViolets
    October 27, 2009

    Speaking also as one who has been on both sides of the podium, it’s not what you don’t know, it’s what you do know that ain’t so. As a math teacher, a large part of my job is being a diagnostician. I’ve got to figure out from the questions in class and the homework what has not been learned right(there’s always those who won’t learn, but that’s another story.) Sometimes, for example, students will try to solve one integral by multiplying two others together, and it’s not clear that they know when they can do this and when they can’t.

    As bad as some teachers are, there is at least some possibility of in-class interaction where this can get sorted out. Video presentations just can’t compete with this.

  11. #11 Matt Springer
    October 27, 2009

    I wouldn’t at all say MIT is concerned with “conferring accreditation, prestige, and social class”. What MIT excels at is conferring working STEM experience, direct access to the best research and researchers, and connections with talented peers who will go on to great things. All these things can and do happen at every decent university, but they’re especially concentrated at MIT by virtue of the fact that MIT pretty much has its pick of the most promising students and professors. A slacker of average intelligence somehow at MIT would benefit not a whit from the social status of the university – in fact his professional life would probably benefit more from a less challenging school.

  12. #12 Hope
    October 27, 2009

    @ Matt Springer (#11) – This is a direct quote from a former boss (now friend) when asked, many years later, why he picked my resume out of a pile when I clearly didn’t have the experience he was looking for: “You don’t find too many slackers at Harvard.” So I would argue that at top-tier schools like these, it’s at least *partly* about accreditation, prestige and social class. The average Joe with the MIT degree will get interviews that superstars at other schools don’t.

  13. #13 CCPhysicist
    October 29, 2009

    How about a list of good textbooks?

  14. #14 Jonathan Vos Post
    October 29, 2009

    One theory of Pedagogy insists on a balance between: (1) Instruction; (2) Assessment; (3) Management.

  15. #15 Mark Eichenlaub
    October 30, 2009


    I agree with the thrust of your argument, but I don’t think you replied to Sebastian Paquet’s post fairly. His claim was that bad lecturing can be replaced by internet lecturing. Claiming that lectures are not the most important part of learning does not refute, or even address, Paquet’s point.

    I’ve reread your final quotation and response to it several times. All I can see is that apparently their points are skew.

    If the most important things is to do problems, and lectures are supplemental, then Paquet’s argument becomes that it’s better to supplement your studies with good online lectures than with mediocre in-person lectures.

    That lectures are not the central element to learning doesn’t mean you shouldn’t skip bad lectures any more than that the condom isn’t the central element to good sex means you shouldn’t avoid bad condoms.

    Paquet implicitly extends his argument to say that if teachers’ lectures are obsolete, then the teachers themselves are obsolete. It seems that this is the part that you’re trying to refute, but other than assigning problems, a trivial task that can also easily be replaced by the internet, you didn’t cite any other essential role for the teacher.

New comments have been temporarily disabled. Please check back soon.