Sowing discord

Hello! Back again after a really splendidly wonderful 3 week holiday.Hope you all had a great Easter too.

Refreshed and energised? Raring to go? Bubbling and, indeed, burbling with enthusiasm? Hmmm, not sure about any of that. However, I have been pondering potential burble-topics, and find myself returning, again, to my KS3 project and the latest new topic with the Year 8s.

And here’s an activity from the opening lesson of the OLD SoW. I need to emphasize that it’s from the OLD SoW as I want to use it as an illustration of how and why I set about revising something.

Here it is, word for word. Remember – this is for a Year 8 class. Remember, too, that in the old SoW, there would have been one tray between 29 students.

You are going to investigate the effect of weeds on crop yield.
Divide a seed tray in two. In one half you are going to sow wheat seeds only. In the other half, you are going to sow the same number of wheat seeds and also some cress seeds (being used as weeds). After 4 weeks you will harvest the wheat; find the total mass of wheat harvested from each of your two crops, and compare these two masses.
Input variable
Outcome variable
Controlled variable
Say which of the two crops you expect to have the larger mass of wheat when it is harvested. Remember to use the word “because” in your prediction, try to give a biological explanation for your prediction.

There then follows a detailed, 8 point method detailing exactly what they have to do, a results table and some heavily guided questions, which I have neither energy nor inclination to repeat here, finishing up with this drearily uninspiring homework, :

You are a government agricultural adviser. Write a letter to a farmer, giving advice about weeding his crop.

Well, I don’t know what you think, but my first reaction is to chuck this in the bin. There’s just so many things horribly wrong about it. Here’s a short list:

  1. Students have no control over what they do – they simply parrot a methodology. They have no ownership – and therefore no interest – in the experiment or in the results.
  2. There’s no real investigation here – students are told what to expect, told exactly what to do, and told what to write for their explanation. It’s not science.
  3. The learning outcomes are very limited – perhaps the best you could say about it is that you find out if your students can follow written instructions.
  4. And one tray for a whole class! I know teachers often like to be in control, but that’s just ridiculous. At any one time, 90% of the class will not have anything to do, except ponder what the input variable is. Like they’ll care.
  5. To add insult to injury, the sheet just looked horrible – a tiny, unreadable font spread over two pages. It was tired, faded, unattractive, not a single picture, photocopied 1000 times and never revised or updated or even just smartened up. Why should students care about a lesson if you can’t be bothered to make the resources look nice?
  6. In short, Ugh.

But having spent much of the Easter holidays on my hands and knees, digging up the ground elder that is threatening to engulf our raspberry plants (and forming a very healthy respect for this splendidly robust and devious weed), I wondered if something could be salvaged.

After all, the actual experimental set up is quite neat – and as I’ve said before, students may hate learning about plants, but they absolutely love growing them – the daily miracle of seeds giving rise to fresh green growth certainly moves them at some profound level, even if they would never admit it. As always, the trick is just to adjust the focus and structure of what they do, so that it becomes like real science, and so that they learn by doing.

Once I had decided that, the rest was easy. Here’s the new sheet with the new lesson plan.

Weeds vs Wheat

As you can see, in the new version of this activity, pairs of students get a tray between themselves. They will have to design and carry out an investigation on the effect of weeds on a crop plant. The experiment needs to be controlled and generate a measurable outcome, but after that they’re on their own. I will supply wheat seeds and a variety of weeds to choose from –  cress, yes, but also ground elder, bind weed, maybe some creeping buttercup…. – but they’re free to bring in their own. Dandelion seeds? Stinging nettles? The experimental design is entirely up to them.

I’ll let you know how it goes!

Ah, the sun is shining, it feels like Spring is finally here. Have a good week.


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