What a homework heatmap actually tells you

There's a version of school data that's all dashboards and percentages and very little use. A child gets "72 percent" and you nod and file it away and nothing changes. I wanted the opposite. I wanted to look at one screen and know what to do tonight.

That's what a heatmap is for, when it's done well. Each topic is a square, coloured from red through amber to green depending on how the child is doing. Strong topics go green, shaky ones go orange, and the ones falling apart go red. You scan it in two seconds and your eye goes straight to the trouble.

The trick is reading it properly, because it's easy to draw the wrong conclusion.

A red square is not a verdict

When a topic shows red, it doesn't mean your child is bad at maths, or even bad at that topic. It usually means one of three things. They haven't been taught it properly yet. They've been taught it but it hasn't bedded in. Or there's one specific misconception sitting underneath.

That third one is gold. Most red squares aren't a wide gap, they're a narrow one. A child who's "bad at subtraction" can very often do the whole thing until there's a borrow across a zero, and then every question goes wrong in the same way. Fix the one thing and the square goes green in a fortnight.

So when I see red, I don't think "do more subtraction". I think "let me look at what he actually wrote", because the wrong answers tell you far more than the right ones.

Watch the amber, not just the red

The red squares get all the attention. The interesting ones are amber. Amber is a topic that's nearly there. A bit of focused practice on something at 60 percent moves it to secure much faster than dragging a red one up from nothing. If you've only got twenty minutes a night, the amber squares are where that time pays back quickest.

Green can lie a little

One caveat. A green square built on three questions is not the same as a green square built on thirty. Early on, when there isn't much data, treat the colours as a rough sketch rather than gospel. It's only after a few weeks of marked work that the picture gets honest. A topic your child has answered twice and got right twice will look perfect, and that tells you very little.

What to do with it

Honestly, not much, and that's the point. Glance at it on a Sunday. Pick the one or two squares that are amber or freshly red. Steer a couple of this week's questions towards those. Then forget about it and let the kid get on with their life.

The heatmap isn't there to make you anxious, or to turn the kitchen table into a performance review. It's there so you stop guessing. Instead of vaguely feeling your child "struggles with maths", you can point at one orange square and do something small and specific about it. That's the entire job.