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2011 April 24

Lectures better than inquiry?

Filed under: Uncategorized — gasstationwithoutpumps @ 15:13
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Education Next has an article Harvard Study Shows that Lecture-Style Presentations Lead to Higher Student Achievement that weighs in on a currently controversial subject in education circles: the value of lectures. There is a longer article about the study also in Education Next: Sage on the Stage by Guido Schwerdt and Amelie C. Wuppermann, and the full report (including the actual regression models fitted) is available from the authors.

The dominant meme among recent graduates of education schools is that lecturing is dead, and that almost any other approach to teaching is better.  This is not a particularly recent meme: John Dewey argued for hand-on learning in place of lecturing over a century ago and Alison King’s article “From Sage on the Stage to Guide on the Side” was published in College Teaching, Vol. 41, 1993 and has been cited at least 186 times.   Thus the conclusion of the Harvard study, that lecturing is sometimes superior, has been greeted by many as heresy, even though the majority of teaching is still done by lecturing.

The study itself evaluated one variable: amount of time spent lecturing versus amount of time spent on in-class problem solving for middle-school students.  The output measurement was scores on standardized tests.

This was not a controlled experiment the way a drug trial might be, with different groups of students being randomly assigned to get different educational treatments.  It would be impossible to do that on a large scale, and the impossible to do a double-blind study.

Instead, the authors came up with a clever trick for using existing data from many students and still get good matching controls.  The used the TIMSS data from “6,310 students in 205 schools with 639 teachers (303 math teachers and 355 science teachers, of which 19 teach both subjects). ”  Information about classroom practices had been collected, including amount of time spent in 8 different in-class activities. On average the teachers spend about 40% of classroom time on problem-solving activities and 20% on lecturing.

One of the problems with using existing data like this is separating cause from effect—do students do better under one teaching style or is that teaching style chosen because the students are better scholars?  The clever trick here is that the students were tested in 2 different but related subjects (math and science), usually taught by two different teachers.  Thus differences in score for a single student control to a large extent for the student-specific variables that usually confound such studies.

Here is their main result:

Contrary to contemporary pedagogical thinking, we find that students score higher on standardized tests in the subject in which their teachers spent more time on lecture-style presentations than in the subject in which the teacher devoted more time to problem-solving activities.

The effect was even stronger in classes where the same group of students were together for both math and science, and stronger still among above-average students. It seems that the popular (with teachers) group work is hurting the brighter students.  The evidence that above-average students are hurt more by avoiding lectures than below-average students is only suggestive, not statistically significant—both groups are hurt by avoiding lecturing.

The authors do put in all the appropriate caveats about the limitations of their study: only 8th graders were in science and math on one particular measurement of achievement (albeit a highly respected one) and the information about pedagogical time use came from teachers’ self reports, which may have strong observer bias, given the dominant meme that one particular teaching style is preferred.

Their conclusion:

Given the limitations of the data, our finding that spending increased time on lecture-style teaching improves student test scores results should not be translated into a call for more lecture-style teaching in general. But the results do suggest that traditional lecture-style teaching in U.S. middle schools is less of a problem than is often believed.

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.

15 Comments »

  1. Lectures are obviously better at delivering lots of information quickly.

    I wonder what the impact is on information retention (past the current school year) and on being able to apply the information in some way.

    I think guided discovery is cool when it works (and horrid when it doesn’t) and *should* make the information more memorable.

    I remember a discussion on the AP Chemistry EDG about a question involving a color change. The teacher reported that all his/her students knew that because they had done the lab and the color change was so drastic and unexpected that it was very memorable. It’s very different to experience something than to just hear about it. Although, would it have been any different if the lab were just demonstrated at the front of the room during a lecture? And, where do scripted labs fall on the lecture vs guided discovery spectrum?

    I know the study just covered math and science, but simulations are popular in history/social studies classes and are, I think, the equivalent of guide-on-the-side learning in that field. Simulations can make the history more real to the students, but they take much longer than just lecturing on the material.

    I do think that teachers need better, stronger backgrounds to effectively teach with guided discovery than they do with traditional lecture. They have to help kids make the correct generalizations from their discoveries and explain where wrong generalizations went off the mark. They also have to be able to motivate a particular group of students to think for themselves, something that can be difficult.

    There’s also a reasonableness factor — how many centuries of material in a given class should elementary or middle school or high school students be expected to re-discover on their own?

    Comment by Jo In OKC — 2011 April 24 @ 15:32 | Reply

  2. I have to disagree with the authors’ conclusion that their study shows that a shift away from lecture format might even have an adverse impact on student learning. It depends on how student learning is measured.

    In the study, learning was measured with standardized tests scores. For me (and my children) an equally important question is “which teaching format lends itself to more creative thinking?” If problem-solving skills had been measured, would the authors have come to the same conclusion?

    It seems a foregone conclusion that students who are given scads of information in a lecture format are going to do better on a test that requires regurgitation than students who are learning by experience. But is that learning? After all of the years of NCLB and teaching to the test, aren’t we coming to realize that while cramming information into kids’ heads prepares them to take tests, it does not foster many of the skills that are required for dynamic problem solving?

    Lectures are certainly valuable. I don’t think we could do away with them. However, there is also a need for guided discovery in the curriculum. Or even unguided, unplanned, discovery.

    Comment by m.k. — 2011 April 24 @ 19:27 | Reply

    • This point is one they mention briefly: they are limited in their conclusion to what they can measure. If you want to optimize an unmeasurable endpoint, it is hard to determine whether you have succeeded. The TIMSS test is better than many standardized tests (it is not a simple regurgitation test), but doesn’t attempt to test creativity.

      Certainly for the math portion, TIMSS is a fair test of problem-solving skills, so if spending more time in class on problem solving rather than lecturing were a better approach for teaching problem solving, it should have appeared on the math portion.

      I don’t think that the authors were claiming that a lecture-only model was best, nor would I. The point, I think, is that the balance has swung too far away from lecturing, so that kids are being left floundering. There *are* teachers out there claiming that lecturing is unmitigated evil, and that inquiry-based learning (no matter how badly done) is always better.

      I think that the real take-away lesson here is that, even if good inquiry-based learning is seen as somehow the ideal, good lecturing is better than bad inquiry-based teaching, and that good lecturing is much more likely to happen in schools than good inquiry-based teaching.

      In my own teaching (at college senior and grad level), there is a lot of inquiry-based learning, except that we call it “research”. But the courses I teach have a heavy lecture component as well. I don’t expect students to be able to rediscover the Smith-Waterman alignment algorithm (though we derive it from first principles, rather than just presenting it as a fait accompli, since the goal is to be be able to develop other dynamic programming algorithms) nor do I expect them to pick up Burrows-Wheeler Transforms on their own. I still struggle sometimes with the magical nature of BWT for sequence mapping—every time I teach it I have to re-read the papers to get the clever data structures right.

      Comment by gasstationwithoutpumps — 2011 April 25 @ 07:12 | Reply

    • However, there is also a need for guided discovery in the curriculum. Or even unguided, unplanned, discovery.

      I guess this makes me wonder what it means to be “in the curriculum” then. I think you can express and model the value of inquiry, and make appropriately leveled “puzzlers” available to students (although providing a question makes it guided discovery in some sense, even if no further guidance is given), but true inquiry in the wild would have to be student-initiated and student-driven. How do you put that in a curriculum?

      Comment by Kate MacInnis — 2011 May 15 @ 11:49 | Reply

      • As an example, in the senior-design project course that I have co-taught, there is pressure from the administration to do industry-specified and funded projects, rather than having the students come up with their own ideas for projects. (The administration is mainly interested in the funding, of course.)

        The instructors have strongly resisted turning the project course into a cheap-slave-labor course. We have no objections to problems coming from industry, and certainly no objections to funding for student projects, but we do not want to assign students to projects or even promise industrial sponsors that any students will be interested in their projects.

        We do guide the students, teaching them how to write design specs, block diagrams, Gantt charts, team management charters, and other crucial planning documents for their projects. We also suggest common problems that they need to address (like power supply choice/design, thermal design, microprocessor choice, … ), but we do not tell them what projects to do. In fact, over the past couple of years we have put the responsibility for finding projects and clients for projects more squarely on the students. We no longer provide faculty and other clients the ability to present projects to the class in lecture: they may list projects with a short description (a few paragraphs) and it is up to the students to probe further if they want to do a sponsored project. (If a student team wants to have a sponsor present information about their project for recruiting more team members, they can request class time, but we prefer that the student team presents the project.)

        Comment by gasstationwithoutpumps — 2011 May 15 @ 12:11 | Reply

  3. My biggest issue is not with the use of standardized tests, which I think can sometimes measure what they say they measure (though not learning in general), but the retention. I’m convinced that a lot of what’s learned is immediately forgotten after the test (hours? weeks? months?). I don’t know if lecturing is worse than other methods, but I think the difficulty of long term follow-up is a real issue in this kind of study.

    I have been intrigued by using success in follow-up courses as a method of testing learning in the original class. That seems like an approach they could try to take here, too.

    Comment by zb — 2011 April 25 @ 18:32 | Reply

  4. I wonder how much of these results are due to heterogeneous grouping, another dominant meme of today. In-class activities are generally done as groups, and the below-average and average students don’t have as much chance to learn when there are above-average students in their group solving the problem, and the above-average students don’t learn as much from activities that are solved too easily for them.

    Comment by DG — 2011 April 26 @ 10:25 | Reply

  5. Thanks for posting this. I generally feel strongly that students are only learning when they’re _doing_ something. I read papers that support that feeling, and since it resonates so strongly in me, I think those results are over-emphasized in my perception of “the field.” The study you talk about here seems well done, and I’m struggling to give it the validity it deserves.

    Do you think that any course of action can be recommended here, though? For me, the biggest takeaway so far is that we shouldn’t require certain styles of teaching if we aren’t prepared to really make sure that teachers get sufficient training in that format. I appreciate that the researches are careful to say that they would not mandate lectures as a result of this study… but what would they do?

    Comment by Riley — 2011 April 27 @ 05:53 | Reply

    • I don’t know what the authors are suggesting be done. In fact, I think that they are bending over backwards to avoid making any policy suggestions.

      My personal feeling is that there has to be a balance between lecturing and practice. Neither pure lecture nor pure inquiry is likely to be optimal. I think that what the study shows is that in many classrooms the balance has shifted too far towards inquiry, and that teachers are attempting to have students do inquiry without sufficient prior knowledge and skills to make it effective.

      Remember that the Socratic dialogs were not records of actual teaching, but works with fictional characters who asked answered questions exactly as the author wanted them to. In the real world, students are not so easily manipulated to “discover” what the teacher wants them to learn.

      Comment by gasstationwithoutpumps — 2011 April 27 @ 07:16 | Reply

  6. Just stumbled across this and wonder if you’ve seen it? It seems to tie together the ideas of inquiry vs. didactic instruction and hetergeneous vs. homogenous grouping. I’d be interested in your thoughts.

    Effects of Collaborative Group Composition and Inquiry Instruction on Reasoning Gains and Achievement in Undergraduate Biology

    Comment by Mylene — 2011 May 9 @ 18:00 | Reply

    • Thanks for the pointer to the article. It reports on a one-time experiment comparing lots of things at once (didactic instruction vs inquiry and heterogeneous vs. homogenous grouping, with a confounding factor of different instructors for the different teaching styles. Their study is far too small to make any sweeping conclusions from, but it is suggestive that homogenous grouping seemed to do better for all ability levels. I am not surprised by their results. Note that there was no comparison made with individuals learning alone—group work was forced.

      Comment by gasstationwithoutpumps — 2011 May 9 @ 20:13 | Reply

  7. I’d like to thank the author here for providing the only reasonable commentary on this research that I’ve seen online. A couple of responses of my own to comments here:

    M.K. says this:

    In the study, learning was measured with standardized tests scores. For me (and my children) an equally important question is “which teaching format lends itself to more creative thinking?” If problem-solving skills had been measured, would the authors have come to the same conclusion?

    I don’t know why so many people allow bone-headed comments like this to escape their lips. How on Earth does one think creatively if one doesn’t have anything to think about? To think outside the box, sure you need thinking, but you also need a box. If the investigators could somehow look at “problem-solving skills,” why would you think that they could possibly come to a different conclusion? Does a student with strong problem-solving skills frequently come up with incorrect answers to multiple-choice tests? I think what’s being described as “creative thinking” here is more like schizophrenia. (And even schizophrenics need some knowledge–even if it’s fantasy–to be paranoid about.)

    It seems a foregone conclusion that students who are given scads of information in a lecture format are going to do better on a test that requires regurgitation than students who are learning by experience. But is that learning?

    Let me ask–did you ever take a look at any TIMSS test questions before making your comment? They release sample questions, and those from the 2003 implementation are online.

    The first question from the Grade 8 math test goes like this: [A rectangle divided into 10 congruent squares is shown. Three of those squares are shaded gray.] In the figure, how many MORE small squares need to be shaded so that 4/5 of the small squares are shaded? A. 5 B. 4 C. 3 D. 2 E. 1

    There is no WAY this is “regurgitation.” (Much of the rest of the items are like this–about evenly divided between multiple-choice questions and correct-response questions.)

    And why is it a “foregone conclusion” that lecture is better for “regurgitation”? You’re just saying things that pair up in your mind–lecture is old school, tests are old school; so they must fit. Really?

    What is “learning by experience”? Is school not experience?

    Do you have anything more than a superficial sense of what you’re talking about?

    Comment by Joshua Fisher — 2011 May 14 @ 09:15 | Reply

  8. […] Lectures better than inquiry? (gasstationwithoutpumps.wordpress.com) […]

    Pingback by The Durability of Teacher Lecturing and Questioning: Historical Inertia or Creative Adaptation? | Larry Cuban on School Reform and Classroom Practice — 2011 June 5 @ 01:01 | Reply

  9. […] Lectures better than inquiry? […]

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