Structure and sequence

How my ideas about initial teaching have changed over time

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I last taught Year 12 physics in around 2018. Since just before Christmas, I have entered the teaching team again and it has brought home to me how my ideas have evolved in this time. That’s the thing about evolution, you don’t notice it happening and so it requires jolts such as this to reveal what has changed.

In 2018, I was fully convinced of the idea of explicit teaching with lots of formative assessment. I had already been blogging about this for six years and was way down that track. Prior to 2011/12, I had also taught a form of explicit teaching, it’s just that I had done so guiltily, thinking it was wrong. By 2018, I held no such misconceptions.

So what has changed since then?

I think I used to teach physics according to the following plan: Teach it early, teach it quickly, front load the hard stuff and therefore create time towards the back end of the course to fix any misconceptions as they arise when students practice loads of questions.

I still think this has merit, especially the idea about giving plenty of practice. It has only recently dawned on me that people interpret ‘revision’, differently with some seeing it as a signal to quickly reteach the course rather than move students towards more independence. When explicit teaching fails it is because we stick with teacher explanation and demonstration long after the students have become relative experts. This means they have no time to build a bank of memories of answering different question types and the moves they used—build their ‘episodic knowledge’—that they can draw on when faced with novel problems.

However, I don’t think I paid enough attention to the initial stages of teaching and this led to too much failure. To be fair, this decreased over time. By 2018, I was fielding far fewer homework queries than I was in 2011. However, looking back, I realise that my plan lacked a on-ramp.

Despite what my critics might imagine or the commentary in my PhD literature review, I believe that it is important to explain the conceptual basis of physics, mathematics or any other abstract subject that relies on simplified models of the world. However, after explaining these concepts, I would then proceed through a series of questions, alternating between demonstrating and asking students to complete the question, while monitoring their success on mini whiteboards.

I don’t think these were sequenced thoughtfully enough. Instead, it was more an attempt to exhaustively cover the different question types in each area. Now, I would sweat which one to introduce first and why. I would create a pair of questions, one of which I would do and one for the students to do, that would be structurally identical in order to smooth that path. To be fair, I was doing this in mathematics in 2018, and I was attempting to do it in physics, but I don’t think I had fully applied the principle. That makes sense, because this is easier to do in mathematics.

And I have realised how many choices physics problems present. For example, if a projectile is launched from a different vertical height to the one at which it lands, there is a rabbit warren of pathways we could follow to work out what is going on. Some involve elegant quadratic equations and thus appeal to more mathematical students. Some are more of an engineering solution to the problem. Back in 2018, I would probably have demonstrated one way—possibly not the mathematically easiest—but explained others before telling students to use any method they preferred. I caught myself doing exactly this earlier this week and it felt strange.

Now, if I was designing a curriculum from scratch, I would be more likely to start with one solution method only and ensure students mastered that before introducing variation. I have become far more anxious about students getting it right the first time, hanging out for those mini-whiteboard answers. I know this is common sense but there we are.

So that’s the sequence. What about the structure?

I used to present students with questions. I would demonstrate the whole thing. That was it. Then, they would have a go. Now, I rely more on scaffolds. What do I mean? Aide-mémoires, suggested methods, rules of thumb. I found myself producing just such a set of scaffolds for projectiles after identifying the key kinds of problems students need to solve. In initial teaching, I rely less on the students gaining experience of different question types—the experiential learning that is so valuable when they are relative experts—and more on front-loading and providing training wheels.

As bad faith actors like to point out, nothing is ever 100% explicit teaching or 100% discovery learning. True. However, it does not logically follow from this that all methods are equal and there is nothing to debate. What does follow is that we need to make conscious decisions about when students should learn from our experience and when they should learn from their own.