Practical: Grinding Frustration

This is the second of three posts about practical work in science.

In the first post I suggested that science trainee teachers (and possibly some qualified teachers too), have a tendency to make assumptions about the value, and the learning, associated with practical work in science. In this second post I’m going to illustrate this with an example and briefly tackle two questions I think are important: whether or not children enjoying practical work is sufficient justification, and whether or not just doing practical will make them better at it. The third post asks whether just doing a practical will improve understanding.

I’ve seen a lot of trainee teachers knacker lessons up with a well run, but ultimately pointless, practical. Whole-class practicals, in particular, are massively time-consuming with many filling an entire lesson. If all that has been learned in that time is “It went blue, sir” then I don’t think that’s good enough.

The problem is usually a confusion over learning objectives. My previous blog set out the way I see learning objectives in relation to practical work but I’ll recount an example. I went to visit a promising trainee teacher a few years ago; the lesson was part of a unit on separation techniques I think; this was certainly part of a sequence on chromatography. When I looked at the lesson plan, saw that it was mainly going to be chromotography of pigments from leaves, and that the learning objective was “To separate leaf pigments by chromatography” I tried to help by asking her what she actually wanted the children to learn. I just couldn’t get past “I want them to separate the yellow pigment from the green chlorophyll”. It’s not fair to pull the rug just before an observation so I let it go and waited to see. Bless those lovely Y8s; they chopped and crushed and ground their little hearts out. They followed the instructions as well as they could, set up their chromatography paper (several submerged the spot in the propanone), and then did a little write up whilst they waited for the chromatograms to be ready. Some got a bit of green and yellow differentiation and the rest didn’t. Whilst they were working I went round and asked a few questions, such as “Can you tell me why you’re doing this?” and “What’s the point of chromatography?” I didn’t even get half answers, just pretty much universal “Don’t know”.

In the feedback session I didn’t get any further, really. The trainee teacher was very disappointed with the lesson. She carefully evaluated the quality of the practical work and made some perceptive comments about maybe splitting the practical into sections and briefing more closely to ensure the leaves were finely chopped, the amount of propanone was reduced, and the papers were set up correctly. But she completely and stubbornly failed to identify the problem, which was that, her ‘learning objective’ wasn’t about learning at all; it was about getting the practical to work. Had the chromatograms come out well, she would have been satisfied with the lesson,  Even when I directly asked the questions “Did the children understand the process?” and “Did the children understand what chromatography was?” and pointed out that they had been unable to tell me anything about these things, she couldn’t really see that this was a much bigger problem than the poor results.

There are plenty more examples where that comes from. Some worked nicely as expected. Some didn’t. All suffered irrevocably from a sense at the planning stage that the practical somehow justified its own existence just by being practical. Often, I find a defensiveness of practical work that I don’t see when pointing out other misaligned learning objectives. That sense that practical is self-justifying can be difficult to change. Why is this difficult?

In the end this boils down to the questions of whether or not (a) children enjoying practical work is sufficient justification, (b) just doing practical will make them better at it, and (c) children will learn important science ideas and/or develop their understanding from seeing the theory ‘in the flesh’. Often I think trainee teachers think, perhaps sub-consciously, that some or all of these are self-evident. I’ll tackle (a) and (b) here and leave (c) to another blog.

For me, enjoyment can’t ever be an end in itself for what happens in science lessons; that just reflects my personal belief in what school is for – no evidence presented. On the other hand, if enjoyment leads to better learning, higher motivation, more time doing science outside lessons, improved post-16 take up, and so on, then the judgement is maybe about balance between enjoyment and learning. I don’t have the expertise to offer a definitive review of the evidence but I’ve certainly been influenced by Abrahams (2009) Does Practical Work Really Motivate? and I’m not convinced practical work is as critical to motivation as is often assumed. The ASPIRES final report makes a brief reference to reduced interest in science after Y9, which might or might not correlate with reduced practical; personally I think it is the  GCSE curriculum content, and looming exams, that is to blame, but can’t offer more than a hunch.

Is it good teaching to explain how to do something tricky and complicated, and then get the children to try lots of examples with very general (that one’s good, that one’s bad) feedback? No, of course not. So why would practical skills be any different? Most of us have had years and years of experience through school, university, and maybe in the classroom, to hone our practical skills. Many of us have probably also taken things to bits and re-built them, developed fine motor, and problem-solving skills, through art and craft and cooking and all sorts. We tend to massively underestimate how difficult it is to extract chlorophyll from leaves, prepare a cheek cell slide, or connect up lamps in parallel. The cognitive load for these things, for children, is very high. In the lesson described above, the instruction sheet and the teacher were both clear about the level of the propanone on the chromatography paper, but at least a third of the class submerged the spot. There was just too much new information for them. These things need breaking down, step by step, with practice or at least immediate feedback at each stage. Without this, children just get used to practicals not working half the time (and working more often for the ‘smart’ kids and more rarely for the others) and accept this is the way of the world. Sometimes there is value in unexpected results, but not if a shrug of the shoulders is the typical response. If we are trying to teach practical skills then we need to plan carefully for those skills, and get precise and accurate work from the children.

Which takes me back to that chromatography lesson. I would have been very happy if the learning objective had been something like “To improve practical skills: use of mortar and pestle to extract plant material; setting up chromatograms; precise working” and then the trainee teacher’s reflection would have been at least a useful starting point. That was an aspect of the intention, but actually, if I’m being generous and assuming the practical wasn’t just picked because it was on the SoW, the stronger intention was something vague about understanding chromatography better by doing a practical example. Failure to separate learning practical skills from developing understanding is a big problem but this idea that doing a practical will improve understanding is, I think, the worst mistake.

Next blog coming up…




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