I love teaching science, but I think it’s a hard subject to teach well. Of course it’s easy to see the challenges in your own area of expertise and gloss over the ones in other subjects but science has a lot of content – a lot of declarative knowledge – and lots of different ways in which that content needs to be applied – lots of exemplars and inferences.
To teach it well, you have to make all this content accessible; you have to teach it quickly and memorably; you have to get children applying in different contexts; and you have to make links explicit.
Take a question like this. It’s from the 2018 AQA Biology Paper 2 (Higher Tier). The Foundation Tier paper uses the same diagram but asks different questions. This is not one of the hard questions on this paper. How do you answer this?
You register, either from the diagram, or the stem, that this is about the reflex arc, which is part of the work you’ve done on the nervous system. You recognise that the drawing pin is just an arbitrary example of a stimulus. You also distinguish the key features of the diagram from all the arbitrary layout and design features. You recall the parts of the system, in order (stimulus, sensory neurone, relay neurone, motor neurone, effector/muscle/gland). You also recall that a signal travels along a neurone as an electrical impulse. The gaps are called synapses, and the signal is transmitted across the gap by diffusion of neurotransmitters.
If all of this happens then you can confidently label P and Q. If you also understand that “Compare how…” means “State how information is transmitted along a neurone (1 mark) and across a synapse (1 mark), [preferably using a conjunction like ‘however’ or ‘whereas’]” then you can nail the other marks as well.
If you don’t recognise what bit of science the question is about, or you can’t see what key information the question is asking for, or some of the key information was never encountered, or can’t be recalled, then you’re stuffed. So how do you teach this? Well, I work with trainee teachers and I see three approaches quite often, none of which tends to work well.
Some trainee teachers try to tell the children the whole thing in more-or-less one go. A common starting point would be “This diagram shows the reflex arc, which is how the body can react very quickly to a painful stimulus. Here you can see a sensory neurone, or sensory nerve, …” With many classes, the children are quickly getting lost somewhere between trying to work out what the diagram does actually show, and processing words like arc and sensory. Sure, with practice, explanations get clearer and more accessible but it’s still the wrong starting point and too much information to handle in one go.
Some trainee teachers do a much better job of breaking up the new information into what looks like small steps. However, they tend to start with “the definition”. A reflex arc is part of the nervous system that transmits a signal very quickly to produce a rapid response to a stimulus. I might be exaggerating a bit (but check Bitesize!) but this kind of formal, abstract statement creates a barrier to understanding that torpedoes all their subsequent efforts to describe diagrams, explain examples, and provide practice.
Alternatively, some trainee teachers end up trying to get the children to teach themselves or each other in a treasure hunt or jigsaw type activity. I have a load of problems with these: large amounts of time are wasted in wandering around and chatting; the task is mostly copying so the children don’t have to think, or it involves something more challenging and lots of children get hopelessly confused; preparing the resources eats up time that would be better spent on something else – having a nice evening at the pub, for example. I’m not proposing a blanket ban (reasons would need exploring in another post) but I’m certain it’s very rarely the right option.