David Klahr writes

My recent post on the value of constructivist teaching sparked something of a debate in the comments. Dan Meyer questioned the Klahr and Nigam study that I referred to. He suggested that the condition described as ‘direct instruction’ is not really direct instruction at all. This is because the students were asked a Yes/No question at the outset of each demonstration and explanation. The key passage in the study is the following:

“Children in the direct-instruction condition observed as the experimenter designed several additional experiments—some confounded, and some unconfounded—to determine the effects of steepness and run length. For each experiment, the instructor asked the children whether or not they thought the design would allow them to ‘‘tell for sure’’ whether a variable had an effect on the outcome. Then the instructor explained why each of the unconfounded experiments uniquely identified the factor that affected the outcome, and why each confounded experiment did not.”

This, to Meyer, suggests that this condition is more like problem-based learning because the students are asked to solve a problem prior to being explicitly instructed in it. I contended that this was nothing like problem-based learning. It is more like stating a learning intention; a way of making clear the point of the exercise. The interaction would also ensure student attention.

I therefore decided to put this to David Klahr, one of the researchers involved. The email exchange is below:

From: Greg Ashman

To: David Klahr

Re: The equivalence of learning paths in early science instruction

Dear David Klahr

I am a part-time PhD student of John Sweller and Slava Kalyuga. I am also a physics and mathematics teacher and I write a blog about   education.

I recently wrote a blog post about constructivism in which I referred to your paper with Milena Nigam. You can see it here:


You will notice that prominent maths educationalist, Dan Meyer, has challenged my interpretation of your experiment in the comments. He suggests that the direct instruction condition is similar to problem based learning because students were posed a question at the outset.

I do not wish to misrepresent your work and so I wonder if I could have a little more detail on this condition such as for how long students were left with this question prior to instruction and whether they attempted to answer this themselves.

Of course, if you wished to comment on the blog then that would be excellent. If not, I would like to be able to quote your reply to this email. If you wish not to be quoted then please let me know.

Kind regards

Greg Ashman

David Klahr was gracious enough to reply and to give permission for me to reproduce his response:

From: David Klahr

To: Greg Ashman

Re: The equivalence of learning paths in early science instruction

Greg: thanks for the invitation to join the blogging about this issue.  I’m not a much of a blogger, but if you want to you can post a link to this paper, which puts the Klahr & Nigam paper in a larger context, and which addresses, in depth, several of the core issues in the blog you mention below, feel free to do so.  Here’s the link:


If you do post it, let me know when its been up for a while and I’ll assume my position as a fly on the wall and peruse the responses.

David Klahr

PS: perhaps the reason that I don’t blog is that I’m too long winded to master the succinctness necessary for the medium.  Its clear that you are a natural:  your 4 sentence summary of Klahr & Nigam is spot on, and shorter than any other version I’ve seen!

PPS: and you can quote this email on your blog  … and I hope you leave in the “PS”, so that your readers will appreciate your summarizing  skills even more.

The linked paper is very interesting on many levels and gives more detail on the experimental method used. It also demonstrates that people have mounted Dan Meyer’s argument before. As Klahr explains:

“…it was suggested that, although the “direct instruction” label is acceptable for an approach in which the teacher designs and summarizes the experiment (as in our type A instruction), that label should not be used in a situation that also includes probe questions (and student replies) as in our type A instruction (Fig. 1). Critics argued that because such interactive engagement with students begins to move from the “talking head” approach often associated with direct instruction toward a type of guided discovery, our type A instruction involves more engagement with the student than is commonly allowed in “pure direct instruction.””

Klahr then goes on to warn us to avoid advocating for general ‘approaches’ and to try to be as specific as possible in describing the conditions that we favour.

I would make a two points:

  • Notwithstanding Klahr’s caution about the idea of ‘approaches’, I find it bizarre to suggest that the Klahr and Nigam ‘direct instruction’ condition represents a constructivist approach to teaching. Of course, if we take constructivism as a theory of learning then any type of instruction is constructivist. However, common understandings of constructivist teaching would not include a teacher setting-up, demonstrating and fully explaining a procedure. I have explored these issues in an FAQ post.
  • It is convenient for constructivists to wish to only allow us to test ‘direct instruction’ conditions that are completely non-interactive ‘talking head’ approaches. I don’t suppose any K-12 teachers actually teach like this and it reminds me of Rosenshine’s fifth type of direct instruction; “Instruction where direct instruction is portrayed in negative terms such as settings where the teacher lectures and the students sit passively.” Indeed, Meyer ventures, “My opinion is that a better test of direct instruction would have had the instructor explicitly instruct students in those four example experiments. Nothing more.” The lack of interaction will mean that student attention is not assured. This would provide a large advantage to any constructivist condition that it is compared with. I suppose that’s the idea.

Meyer was quite insistent that I answer his questions on this issue, even though I dispute the assumptions implicit in them. And so I would now like to draw a contrast. As a proponent of explicit instruction, I have provided plenty of evidence to support my position. Discussions of the nature of this evidence are interesting and important but there is certainly no lack of it.

Dan Meyer, however, has offered no such evidence to support his widely espoused views on maths teaching.


3 thoughts on “David Klahr writes

  1. Stan says:

    Well that was a satisfying addition to the discussion. Now it is much clearer what was done.

    More usefully it exposes even more clearly the problem in the discussion – when people are more attached to their labels than the details of what these mean to them progress comes to a halt and then reverses. (By people I am not referring to Greg who has done all the work to clear up the mess here.)

    This is a discussion between two experts in studying education most teachers are not trained in research methods and interpreting their results. There are folks out there who will interpret a vague term in quite extreme ways. If what teachers do is important it might be time to dump some jargon that has become so ambiguous it is worse than useless.

  2. Meyer’s methods appear to me to be a combination of the “struggle is good” philosophy with “just in time” learning. They also rely on eliminating what he calls pseudocontextual problems which he believes are a turn-off to students because they need and desire problems that are relevant to them and real-life in order to be motivated to solve them, but I’m focusing on the first two I mentioned.

    Regarding struggling, I’m not against students doing so, if it is done right. In my classes, I require my students to answer warm-up questions at the beginning of class. I use two types of questions: One is a review-type question to apply what they recently learned. The other requires them to apply their prior knowledge–or what was familiar–in a new or unfamiliar situation. Some may view this as an inquiry-based approach, or an application of the “struggle is good” philosophy that adherents of Common Core seem to say is necessary to develop perseverance in problem solving, as well as the all-important and frequently undefined “grit”. I view a short amount of struggle as appropriate provided that explanation is provided shortly after. That way, even if students do not succeed in solving a problem, it serves to whet their appetite for an explanation that they might otherwise tune out.

    The approach I describe is sometimes referred to as giving problems within a student’s Zone of Proximal Development (or ZPD), a term used by Vygotsky, and taught in ed schools. (It is probably one of the only theories from ed school that I agree with). The student is made to stretch beyond his/her prior knowledge. An example: If students have learned to factor trinomials with all positive terms, then a problem in which a trinomial has some negative terms will be different from what they’ve solved–but the method they used for all positive terms can serve to lead them to factoring it. I’ve seen this happen. And the students who didn’t figure it out are more receptive to the explanation.

    Struggles that I find counterproductive occur when the leap the student has to make is too big; i.e., the problem is likely out of his/her ZPD. There may not be enough of what is called “scaffolding” (i.e., intermediate problems with slight variations to lead them to making leaps as in my example of factoring trinomials). Or it may require some new knowledge to be acquired. Advocates of this approach believe that the need for this knowledge is motivation for them to now learn the new procedure or concept in a “just in time” manner. Now this approach may be good for introducing a lesson in which the new concept is to be learned. It whets the appetite just like the warm up “stretch” problems I’ve been talking about. But some concepts and procedures are best developed to mastery first before applying them. It then becomes something like tossing someone who doesn’t know how to swim in the deep end of a swimming pool and shouting out directions for how to swim.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.