Saturday, April 30, 2011

Lecture versus Students Figuring Things Out

I've kept this page up in a tab on my browser for a week. Each time I come back to it, I'm not sure what to do with it. EdNext* is describing a study done by researchers from Harvard. From the intro:
A new study finds that 8th grade students in the U.S. score higher on standardized tests in math and science when their teachers allocate greater amounts of class time to lecture-style presentations than to group problem-solving activities.  For both math and science, the study finds that a shift of 10 percentage points of time from problem solving to lecture-style presentations (for example, increasing the share of time spent lecturing from 60 to 70 percent) is associated with a rise in student test scores of 4 percent of a standard deviation for the students who had the exact same peers in both their math and science classes ...
It seems clear to me that we do not learn as well when we're passive as when we're active. This study seems to argue the opposite. The article points to another article that goes deeper into the research; at the end of that one, they do say:
Newer teaching methods might be beneficial for student achievement if implemented in the proper way, but our findings imply that simply inducing teachers to shift time in class from lecture-style presentations to problem solving without ensuring effective implementation is unlikely to raise overall student achievement in math and science. On the contrary, our results indicate that there might even be an adverse impact on student learning.
My take on any sociological research, which includes education research, is that there are too many variables involved to do really good research. What happens is that many researchers frame a question in a way that is bound to bias the results toward a conclusion they already favor.

But still, I'd like to be able to explain a result like this one.

I know from experience that teaching from one of the 'reform' (back when reform meant something else) calculus texts would have been very hard without getting trained. I was trying to find ways to change my teaching, and would have worked from the project-based 'reform' texts, but couldn't see how to do it. It became clear to me that you couldn't change the way math is taught by providing a good textbook. The way classrooms 'should' work has been imprinted on us through 16+ years of sitting in classrooms as students. It's pretty hard to do something different, and then to do that different thing well. So I do agree with their conclusion that newer teaching methods need to be implemented in 'the proper way', which involves lots of work retraining ourselves.

Jo Boaler has done lots of research on math education. I'd like to know what her take on this study is.

What do you think?

*EdNext is part of the Hoover Institution, which is a conservative think tank.


  1. We were spitting mad about this. To me it looks like sloppy research, and then reprehensible reporting on the sloppy research. My clleague Dave has a well thought out commentary at

  2. I think this research needs to be taken seriously. Yes, there are flaws with it, but there are flaws to point out in any sociological, in this case psychological research. It may be invalid, yes, but we don't know that and let's not jump to whatever conclusions we would most like to have.

    This study, by itself, says nothing - no single study ever does. However, it is in line with international studies which show that nations that perform the best on TIMSS spend the most time on teacher talking, and the least on students talking. Hong Kong is an example. What we've heard about asian mathematics classrooms being so problem-solving oriented is a gross misrepresentation, based on a small set of Japanese classrooms.

    I think the case here is not whether students are active or passive - following a lecture is a very active endeavor, if one hopes to really understand the content of the lecture.
    To me, the difference is rather in what our goals are - why are we teaching mathematics in the first place? I teach it because it is a fascinating system of thought, and I think that to truly understand it one must participate in it, which is difficult to accomplish through lectures.
    On the other hand, perhaps some of us (me, for instance) have been over-doing the problem solving approach, ignoring the different restraints on mine and students' time that would make good direct instruction a wiser choice in some cases.

  3. Thank you, John!

    The biggest problem Dave points out is that teacher reporting isn't a good way to measure what teachers do.

  4. Hi Sue,

    I agree with much of what Julia said: this study needs to be taken somewhat seriously, although it is only one bit of evidence that lecturing is better. If we start seeing many studies like this, then I will consider changing my style of teaching (back to what it was 10 years ago).

    Julia also pointed out the importance of goals. I think the most important parts of this study is that they were based on standardized test scores. Thus, the worth of this study depends on how much those standardized tests match up with your goals.

    Additionally, Dave (via John's link) makes the excellent point about the problem with self-reporting: I have seen many different teachers teach over the years, and the vast VAST majority of teachers who claim to do some sort of problem-solving-based classroom are actually just lecturing (In my opinion. I will also note that I am in this category, although I am rapidly moving toward a true problem-solving-based classroom). So I would wager that the majority of the teachers in the problem-solving group are actually doing some version of direct-instruction.

  5. One of the things that frustrates me most about this whole lecture-versus-problem-based-instruction tug of war is the seeming lack of awareness on both sides of the skill and emotional intelligence of the instructor in setting up and carrying out classroom instruction. This feels like a pretty giant factor to me, and a pretty giant oversight in the analysis.

    As both a teacher and as a student, I have experienced lecture-based instruction of such exquisite attunement and sensitivity to students' learning it has taken my breath away.

    By the same token, I have experienced student-centered, problem-based instruction of such utter and comprehensive obtuseness it has left me wondering how any student ever manages to construct (much less to retain) any knowledge of any kind.

    And of course, I too have experienced outstanding problem-based instruction and block-headed lecturing... just like everybody else has.

    So much depends upon the perceptiveness and skill of the instructor in any teaching method, it does not surprise me that researchers can find successful learning in lecture-based classes and total failure to learn in problem-based classes. One can easily find whatever one is looking for, if you just block out enough variables.

    I also find it interesting that some of the heroes of the problem-based, student-centered approach (including Judy Kysh and Jo Boaler) advocate the use of different techniques for different material and different students in different situations.

    So I guess my real question is, why can't the research on the effectiveness of different teaching methods be as flexible and responsive as the developers and practitioners of those methods are themselves?

    - Elizabeth (aka @cheesemonkeysf on Twitter)

  6. I'm not convinced that 4 percent of one standard deviation is a large difference. I don't have the data, but I would estimate that this is less than the difference of get one more question correct on a 100 question test.

  7. Can anyone offer any advice on moving from lecture based to project based teaching? Or even just incorporating more project based learning in my classes? All my math classes, with one exception in college, have been lecture based. However, I'll be teaching on a block schedule next year and I know I can't lecture for 90 minutes -- their brains will leak out their ears! But I have no idea how to implement or manage project based learning. Help!

  8. Meg, It's a long road, changing your style that much. I started out interspersing my mini-lectures with practice sessions. That at least will make a long block more bearable.

    But in the long run, for each unit, you want to think about why you care that the students learn it, and help them to care, either with real-world applications or puzzles, or some other inspiring entrance to the ideas.

    I'd be happy to chat if you'd like. Email me at suevanhattum on the warmer mail system, if you'd like to connect.

  9. Anonymous, I'm not too dazzled by the 4% of a standard deviation either, even if the difference in results is significant (must have been a huge sample!) it's hardly worth changing methods over.

    Cheesemonkeysf, as far as I gather, social science is always a compromise between quality and quantity. In this case, paying attention to different factors such as teacher, class, topic, context - it's just too much to be able to study quantitatively with a large sample. So researchers go for averages, which is better than nothing, at least.

    Meg, I use a lot of investigations in class, and found the transition from lecturing to be quite simple in principle, although it took some time for students to get used to it. I suggest asking instead of telling - give students some time to come up with their own solutions, where possible. John, at Zero Knowledge Proofs, has a nice example about factoring trinomials here:

    In a similar vein, I usually have students figure out themselves how to solve different types of quadratics, as well as use trig to find area of triangle, and other suitable mini-topics. It's a start, at least, and in my experience students really enjoy such tasks.

  10. I am so late to this party, but what the research seems to actually be reporting is that good math teachers choose to lecture more (or, choose to report that they lecture more).

    I guess that's somewhat interesting, but not earth-shattering by any means, nor is it a good justification for telling people how to change their teaching styles.

    You could set up a better study by asking the same teachers to vary the time spent lecturing to different classes, but that has the problem of not being a blind study, and you could get effects based on which method the instructors want to work better.

    My guess of an explanation: Someone who likes math, understands it, and is passionate about teaching it will be better at talking about it and will choose to do so - much like you do here.
    Someone who really doesn't care (or worse, really doesn't understand) will find it much easier to just work through problems.


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