Confused? Good. You might be about to learn something.


First published at physicsfocus.

It’s never the most comfortable of feelings to have some aspect of your work described as “appalling”. But that’s what greeted me yesterday morning when I scanned down the comments thread for the most recent video I’ve made with Brady Haran for his Sixty Symbols channel


The source of the opprobrium? Well, the video in question was on the topic of entropy. I should have learned by now not to go near the topic of entropy with a barge-pole for a YouTube video because it’s a subject that really can’t be done justice in five or ten minutes. But I had attended a brilliant and inspiring colloquium by Daan Frankel on entropy and self-assembly shortly before the video was filmed. As part of his talk Daan had described the pioneering work done by Sharon Glotzer’s group at the University of Michigan on the role of entropy in the self-organisation of nanoparticles. Glotzer’s group has neatly shown how entropy can be exploited to drive an ensemble of nanoparticles to an ordered state.

Yep, that’s right. Entropy produced order, not disorder. (I enthusiastically recommend Glotzer’s TEDx talk for more on this.)

I thought that this departure from the traditional view of the role of entropy would make a great subject for a Sixty Symbols video and suggested it as a topic to Brady. We filmed it and, as ever, Brady and I had some healthy and robust debate about the role of analogies and metaphor in explaining the physics. Overall I was pretty happy with how the filming went. (As I’ve discussed elsewhere, we academics do not get involved with the editing of the Sixty Symbols videos – that’s all expertly done by Brady. The first time we see the finished product is when it goes online.)

So why does YouTube commenter TheRumpus feel so strongly that the video doesn’t work? Well, you can of course read his comment for yourself but it was the final two lines which particularly resonated with me (for reasons I’ll go into below):


As I’ve explained over at YouTube, Sixty Symbols videos – certainly those with which I am involved – are not meant to be tutorials or mini-lectures. No-one should expect to come away with a solid understanding of entropy on the basis of watching a YouTube video (otherwise why would we bother with setting problems, coursework, lab work, and/or projects for thermodynamics courses – or, indeed, any aspect of physics?). Sixty Symbols videos are instead a conversation with physicists about particular topics that interest and enthuse them – they represent a taster, rather than a tutorial. (I discussed my qualms about YouTube edutainment in a physicsfocus post last year.)

Leaving those points aside, TheRumpus’s comment raises a much broader and rather more subtle issue. Is adding to confusion necessarily a bad thing? Should we always avoid the possibility of confusing the audience when we’re discussing or explaining physics? Or could confusion actually aid the learning process?

That certainly seems like a rather, errmm, unhinged set of statements for a university lecturer to make. After all, don’t I aim to make my lectures as clear as possible so as to enhance student learning? Don’t I revise and re-revise the notes I give students in an attempt to eliminate any hint of ambiguity? And isn’t the quality of my teaching assessed (via, for example, Student Evaluation of Teaching questionnaires) on the basis of its clarity?

Yes to all three questions. But could this focus on eliminating confusion and ambiguity actually be doing students a disservice?

A fascinating article was published in The Chronicle of Higher Education back in August on exactly this topic. In “Confuse Students to Help Them Learn”, the work of Derek Muller, of Veritasium fame, and both Sidney D’Mello (University of Notre Dame) and Arthur Graesser (University of Memphis) on the role of confusion in learning is described. D’Mello and Graesser’s work challenges much of the received wisdom about teaching and learning and I’ve made time over the past couple of weeks to read a number of their publications (which are all available here).

The title of a paper published earlier this year by D’Mello, Graesser and colleagues nails their colours to the mast: “Confusion can be beneficial for learning”. The abstract does a very good job of bringing out the key points of their study. Here’s an extract:

“Confusion is expected to be more the norm than the exception during complex learning tasks. Moreover, on these tasks, confusion is likely to promote learning at deeper levels of comprehension under appropriate conditions”

This flies in the face of everything we’re told about the characteristics of effective teaching, but, I suspect, will nonetheless chime with many physicists’ experience of how they came to understand complicated concepts in, for example, quantum theory, relativity, and – oh, let’s say – thermodynamics and statistical mechanics.

Over a decade before D’Mello et al.’s paper was published, Kurt VanLehn and co-workers had found that in order for successful learning to take place in physics, an ‘impasse’ (as they describe it) has to be reached. In other words, the student must be confused at some point in order to learn.

Or, as Derek Muller puts it in that Chronicle of Higher Education article:

It seems that, if you just present the correct information, five things happen. One, students think they know it. Two, they don’t pay their utmost attention. Three, they don’t recognize that what was presented differs from what they were already thinking. Four, they don’t learn a thing. And five, perhaps most troublingly, they get more confident in the ideas they were thinking before.”

So, “add[ing] to the confusion about entropy”, as TheRumpus puts it, need not necessarily be a bad thing. What is of key importance, of course, is the student reaction to that confusion. We need to be very careful to ensure that the learner does not switch off entirely (and D’Mello and Graesser are at pains to stress this).

But when confusion triggers a response like the following, it’s difficult to argue that we should always aim for maximum clarity:


“Time to do some reading on this.” What more does any teacher want to hear?



Author: Philip Moriarty

Physicist. Rush fan. Father of three. (Not Rush fans. Yet.) Rants not restricted to the key of E minor...

10 thoughts on “Confused? Good. You might be about to learn something.”

  1. Well, correct physics shouldn’t cause any confusion. It is only the weird theories which masquerade as physics confuse students. And the unfortunate students have no option but to believe in what is taught to them as physics to progress in their career blaming their own ignorance for the confusion.


    1. “Correct physics shouldn’t cause any confusion”. With all due respect, I beg to differ. Quantum mechanics can be exceptionally confusing for an undergraduate (and postgraduate, and, for that matter, professor!). Try explaining reciprocal space and band structure in a clear and non-confusing manner to a student who has not come across the concept previously.

      Here’s Feynman on the matter of confusion:


      1. Yes, correct physics shouldn’t cause any confusion. And by that, I also mean ‘physics’ which causes confusion is not correct. That includes your relativity and quantum physics.

        Every observation (including your double slit experiment) that is claimed as proof of these illogical theories can be explained by simple reasoning and commonsense without the need for any ‘confusing’ and illogical propositions like warping of spacetime/ time dilation/ live but dead cat etc.


  2. Great point Phil. Science is not just about being told ‘facts’ by an ‘expert’, and then regurgitating these as required. Physics can be confusing, QM and Relativity being two obvious examples. Being confused from time to time is good for you – it forces your brain to work!


  3. Hi Phil,

    Well I wish I’d read this before I left my comment on another post of yours. This is great stuff and the links are really helpful.

    When I was in education my primary pedagogical interest (and pleasure) was working with first year students, a situation in which the key concepts introduced are often in most stark contrast to their prior understandings. Confusion (and I really like the etymology of that word by the way), and even outright antipathy to new ideas, is to be both expected and attended to.

    I guess the trick (which I’m not going to pretend I ever perfected) is to support a form of confusion which allows them to proceed beyond the impasse it represents, rather than being disheartened or alienated by it.

    I know you’ll be familiar with the idea of Threshold Concepts and it’s association with the ‘troublesome knowledge’ outlined by Perkins, which I always found useful. Certainly in terms of the metaphorical framing in which education is understood as a kind of journey (a ‘course’ of study in which one makes ‘progress’ for example), the threshold image aligns well with the notion that the learner might come to a troubling ‘impasse’ that they need to be escorted out of toward the sunny uplands beyond.

    For me this is one defence of entertainment. I tended to stud my lectures with musical interludes, games, and lots of familiar pop-culture references, so whilst the material might be confusing at least the experience is fun. I think even education needs to include a bit of fan service, if for no other reason than to keep them coming back.

    Best wishes



      1. Hi Phil,

        Thanks for the offer, I’d love to put something together on that theme as a guest post. Now I’m out of academia I really miss playing with these ideas so would welcome the opportunity to revisit that stuff. How do we do that?

        Best wishes



    1. Hi, Fred.

      Please send me a Word document with your post (with links embedded as in any Word document) and I’ll upload it. My email address is

      I usually run as far away from Word as possible — I am a LaTeX fan — but for WordPress I can simply cut and paste the text.

      Thanks for accepting the invitation. i look forward to reading your post.



Comments are closed.