I delivered some CPD tonight on recovery curriculums that I thought I’d post here. I’m flat out of energy so my annotations here are limp at best. Sorry in advance. Still, might be helpful.

In advance of the session I read a lot of articles about science recovery curriculums. All of them featured magic time bending. Lots of magic time bending. Some schools are miraculously managing to fit six months of year 10 content into three weeks at the start of year 11. Either they:

1. Are magic time benders
2. Do a terrible job under normal circumstances and waste loads of time
3. Are talking nonsense

It’s particularly unedifying reading all the hot takes around about how Covid proves we need to do <<insert thing I’ve been banging on about for years>>. I’m much more interested in people changing their mind because of Covid. The below definitely builds on things I have thought and believed for a while, but the practical take home is something I have never done well enough and would like to think more about. So maybe I’m pointing the finger at myself too. I can live with that.

My argument starts with the below two pieces of knowledge.

These two pieces of knowledge belong together. We need to balance equations because of the conservation of mass. The conservation of mass is expressed in a balanced equation. But, and this is the key bit, plenty of students are blissfully unaware of that connection. They can balance equations, and they can explain and apply the conservation of mass, but they don’t know that one necessitates the other.

We can add more nuggets and see how things start to build up. Each piece examines a different aspect of the content, and each one might, or might not, be connected in the mind of the student. So one student might know A, B and C but only have B and C connected, another might know A, B and D and have A and B connected and so on.

The point here is that as the number of pieces of knowledge builds up, so do the possible combinations of knowing/not knowing as well as the connections between items. And thanks to Covid, we all know how exponentials work: you can end up with zillions of different combinations for any given class.

The logical corollary of this is that second sentence. It becomes close to impossible to reliably figure out which student knows which specific thing and has which connections. It’s so impossible as to be undesirable, and it’s for this reason that summative assessments don’t actually try to do this and things like QLA are a bit daft (as I have unedifyingly banged on about before).

So that strikes out a key plank of the whole recovery thing. It’s impractical, implausible and impossible to actually work out what a student knows to any kind of granular level. Furthermore, even if you could work it out, what are you going to do? You don’t have a magic computer that can tailor instruction to individual students’ knowledge webs. So why bother with the whole “big assessment to establish gaps” thing?

The next step in recovery curriculum thinking tends to be to identify the most important or highest leverage item in the syllabus, and spend time on that. The problem is, in science at least, there probably isn’t anything like that.

Anyone remember the question below?

4% of this exam was on this guy called Chadwick who, if the twitter storm after the exam was to be believed, nobody had ever heard of. Truth is, he was on the specification all along, but nobody taught him or bothered to learn him – assuming that it was so niche it just wouldn’t come up. Even tried and tested topics get asked in subtly different ways that tease at different strands of knowledge. We pay the brainboxes who write exams for a reason and – again in science at least – you can’t outsmart them by not teaching material that you think won’t come up. You’re just potentially screwing your students out of a bunch of marks.

I think instead we need a different approach to diagnosis and prioritisation, one that emphasises the difference between prior and prerequisite knowledge.

Let’s say you’re about to start a lesson on terminal velocity and you had the list of questions below. Which ones are actually important to your lesson today?

So in my opinion, the only ones that matter right now are:

All the others are important, but you can actually understand terminal velocity without them. If you don’t understand the nature of air resistance or friction you can’t really understand terminal velocity, as you can’t understand why the sizes of those forces would change as velocity changes. And the difference between speed and velocity is also pretty fundamental here (though actually looking at it again I think it’s arguable).

My point isn’t that the others aren’t important, but they aren’t required to understand terminal velocity. This is what we call prerequisite knowledge: the stuff without which you cannot access today’s learning. This is opposed to prior knowledge: stuff which students should know because you’ve taught it to them, and might be related to the stuff you are teaching today, but not strictly necessary.

If you’re a science teacher, here’s a fun activity to try – which of the below are prior and which are prerequisite?

To be clear, I’m not saying prior knowledge isn’t important. It is important. Your students need to know it. They just may not need to know it today. I’m going to say that again before someone pitchforks me on Twitter:

And, perhaps more importantly, you need to be strategic. Let’s say you’ve planned a lesson on topic B. In your questioning you find out that students don’t know topic A, which is prior knowledge, so not prerequisite. If you decide to go back over it and cover it then you:

1. Push off carefully laid plans, which won’t be implemented as well second time around because of the time lag from when you first planned them
2. End up doing a worse job teaching topic A than you would if you took some time to plan it properly

Doing something ad hoc is always going to be worse. On the hoof explanations, checks for understanding and practice sets are always going to be worse than carefully planned ones. What will end up happening is you will do a five minute verbal recap of topic A then go “right does that make more sense?” see a load of nodding heads, move on to topic B and find a week later that you wasted five minutes of your students’ time because you didn’t properly explain, check for understanding and give out practice sets.

So we end up having to take very different approaches to these very different types of knowledge items:

In more depth:

Sadly, you aren’t going to have time to go over every topic. You’d better start accepting that now. Unless, of course, you have magic time. Being really charitable, we can call additional after school sessions and intervention and things as “magic,” which means that you may have time to revisit things. It’s up to you how to prioritise the time you have, but if something is prior, not prerequisite, the key is to plan it for another time, not today.

Track 2 is a lot harder. As a teacher it feels really difficult to push things off like this but, in my opinion, it’s got to get done. If you identify a gap in prior knowledge, your first thought should be “ok, I will have to do that another time”, and then you go back to track 1. But if something is prerequisite, then it’s track 2 and you need to do something about it right now. The key here is to think about that before the lesson. Sit down and really try to figure out “which questions do they need to be able to answer before they can access today’s learning?” and ask those questions. Then be ready for the eventuality that they can’t answer them. Re-model. Re-teach. Check for understanding. Give practice. So long as you’re prepared, it should work.

So that’s that. You might know all this already, you might do all this already – good for you. But it’s definitely something I need to think about more. I also realise I should have published this six weeks ago but hey, I don’t have a magic time bending machine.