Carl Wieman plenary at SIGCSE 2010: The brain’s a muscle?

March 12, 2010 at 6:32 pm 16 comments

Carl Wieman‘s talk at SIGCSE 2010 was intriguing.  I really liked the teaching practices that he recommended.  I didn’t buy his explanations for why they were good.  But as I’ve started poking at the references he provided, I’m finding that there is evidence to support at least some of his claims.  I’m downloading more in order to dig deeper.

(Yeah, I was too far away for this photo.)

Carl said that the goal of his institute is both to have students learn more effectively and to make teaching more efficient and rewarding for the teacher.  He recommends a model of carefully identifying the components of expertise, measuring the development of expertise in students, and iteratively experimenting and assessing to get it right.  He identified expert competence as having lots of facts, having a good knowledge organization framework, and monitoring one’s own understanding and learning. The goal of science education is to get students to be more like that.

Carl first presented evidence that we’re not doing well now.  He cited a paper by Richard Hake describing a 6,000 student survey (Yes! Three zeroes there!) showing that “On average, students learn less than 30% of concepts that they did not already know in lecture classes. Lecturer quality, class size, and institution doesn’t matter.”  With improved methods, that can rise to 40-60% or better.

He gave four principles of effective learning and teaching. (1) Motivation which he said is “essential, but often neglected.” (2) Connecting with and building on prior thinking. (3) Applying what is known about memory (where he recommended Robert Bjork’s work). And (4) explicit authentic practice of expert thinking.  This last part is where he went into an argument that I didn’t quite buy.  He said that “Brain development is much like muscle development.” It takes lots of practice, and that’s why motivation is so important.

Now, when I took cognitive science in the late 1980’s and early 1990’s, I was told explicitly that the brain was not a muscle and shouldn’t be thought about that way.  It wasn’t about practice.  So, I started digging into it.  Looks like Wieman is right!  There are these really intriguing studies showing that simply telling kids that the brain is like a muscle leads to better learning.  Of course, it’s still controversial, and it’s not about the brain being biologically similar to muscle. It’s about thinking about brain development as being like muscle development. Practice matters.

Carl pointed out errors that we make as teachers by not taking all of this into account.  For example, weighting exams most heavily in determining course grades is counter-productive.  Making exams important leads to cramming, which does result in better exam performance — and minimizes long term retention of that information.  You learn it only for the exam.

Then Carl claimed that lectures tend to cover too much material. We should try to teach less per lecture because there are limits on short term memory.  We shouldn’t try to teach more than seven concepts in a lecture, because we can only hold 7+/-2 subjects in short term memory.  Now, I don’t buy this one.  The duration of short term memory is at most 10 minutes, or as short as 30 seconds.  That’s not lecture-length times.  Cognitive load is certainly a critical issue, but I don’t know of evidence (and can’t find any yet) supporting the argument for no more than seven concepts per 60-90 minute lecture.

Several of the methods that Carl promoted really resonated with me.  His argument that we should start top-down, with an interesting problem and then explain what’s needed to solve it (as opposed to bottom-up, providing background knowledge, and then problems that integrate that knowledge) meshes with our notions of contextualized-computing education.  He’s a big fan of peer learning and the use of “clickers” in classrooms.  He provided lots of pointers to what he called “more scientific forms of teaching.”

Carl’s talk has me digging into areas of educational psychology than I’ve not looked at in a long time.  He’s also got me thinking about how to implement some of his methods in computing classrooms.  How do we give “quick, effective” feedback on homework?  No way is entering a whole program into an IDE then interpreting Java error messsages counts as “quick and effective”!  (Alex Repenning had a great quote from a student in his talk: “Computer science class?  That’s where the teacher gives you a program on the board, then you type it in, and it doesn’t work.”)  How do we provide homework or in-class activity that gets at expert computing thinking skills, like debugging and testing, without overloading that with also having to design programs, write programs, enter programs, and fight the compiler’s error messages?

Another great note keynote well worth the price of admission, er, the time and expense to travel to Milwaukee for SIGCSE 2010.

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16 Comments Add your own

  • 1. Barry Brown  |  March 12, 2010 at 9:17 pm


    Have you read Brain Rules by John Medina. Having read that book about a year ago, Wieman’s talk sounded eerily familiar. Medina, a molecular biologist, uses what we know about how the brain works to make twelve recommendations that would improve the way we teach and learn. Some of them map directly onto Wieman’s proposals.

    It’s a relatively quick read. Highly recommended.

    • 2. Mark Guzdial  |  March 12, 2010 at 11:34 pm

      Thanks for the suggestion, Barry. No, I hadn’t heard of it, but just downloaded a sample for my Kindle.

  • 3. Amy Bruckman  |  March 12, 2010 at 11:26 pm

    Uh oh… so next year you have to make it worth a *trip to China*? 😉

    • 4. Mark Guzdial  |  March 13, 2010 at 12:08 am

      That was a reference to Steve Wolfman picking on me during the open plenary (yes, in front of 1200 SIGCSE attendees). I said in my last blog post that Sally Fincher’s talk was “worth the price of admission.” Steve pointed out that, as Associate Program Chair, my “admission” was free. Trying to be more careful with this blog post…

  • 5. Anne  |  March 13, 2010 at 11:08 am

    Miller’s original work on the magic number was in 1956 but there is a nice write up on Wikipedia,_Plus_or_Minus_Two

  • 6. Leigh Ann  |  March 13, 2010 at 11:57 am

    The reference “How people learn” is a good start, but if you look at the IES practice guide on organizing instruction and then to the reference list to several of their recommendations you can see some good evidentiary support for a lot of his guiding principles.

    • 7. Mark Guzdial  |  March 13, 2010 at 1:40 pm

      I’ve read “How People Learn” several times. Several of the things that Carl was talking about are newer than “How People Learn.” I just looked up the IES Practice Guides. Thanks for the tip, Leigh Ann!

      • 8. Leigh Ann  |  March 15, 2010 at 2:46 pm

        I use the practice guide as the first reading in my Intro to CSED course for two reasons. First it puts forth some really good suggestions for good teaching, but second – if you read the description of how they evaluate whether or not a practice gets into the report and what is high/med/low support it makes for a great discussion about ed research as well.

  • 9. Mark Guzdial  |  March 13, 2010 at 1:04 pm

    Carl’s slides are now available, linked at in both PDF and PPTX formats.

  • 10. Stephen Gilbert  |  March 14, 2010 at 4:48 pm

    Mark wrote:

    “How do we give “quick, effective” feedback on homework? No way is entering a whole program into an IDE then interpreting Java error messsages counts as “quick and effective”!”

    I don’t know. When I compare that to any other class it seems remarkable quick and effective because you don’t need to wait for a week to get your marked up paper back from the teacher. I also don’t see the Java error messages as being much more inscrutable than the messages you get from Word when your grammar is incorrect.

    I also think that tools like Javabat or Web-Cat that give the student feedback on correctness are even better. Imagine if Composition 101 students could use a tool that not only told them when their spelling was correct, but whether the conclusions they had reached were correct.

    • 11. Mark Guzdial  |  March 15, 2010 at 10:48 am

      Stephen, Composition 101 students can get that kind of feedback. They hand their paper to a peer or adult who can give them that feedback. That’s quick and effective. We can’t do that in the same way with code. I hope nobody really believes that Word is teaching anyone grammar. That’s better done by a person. For math, there are wonderful tools, from calculators to Geometer’s Sketchpad to (for advanced students, who can handle more overhead) Mathematica, that can give quick and effective feedback, without undue overhead. Javabat and Web-cat (and Problets) are clearly in the right trajectory. We need more, and at more stages of the curve.

  • 12. Eric Freudenthal  |  March 15, 2010 at 8:40 pm

    This immediate feedback thing is important. That’s part of why our media-computation variant (MPCT) has soooh many tiny projects. Many are just 4-6 lines of code – without even a function call. Since the interactive command line is in the same scope, students can easily check variable values.

  • […] exactly backwards, according to the cognitive science. You start out with motivating circumstances and low cognitive load practice, and then move on to […]

  • […] the other hand, their experience meshes with the “brain as muscle” notions that Carl Wieman talked about at SIGCSE.  They felt that they really learned from all that practice in the […]

  • […] is a really nice piece on a lecture by Carl Wieman, whom I have mentioned previously.  In one page, the summary hits most of the key ideas in How […]

  • […] in Orlando in early January, Nobel laureate Carl Wieman gave a talk where he referenced the famous Richard Hake 6000 subject study.  One of the results of that study is that traditional lecture only results in students learning […]


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