My eldest daughter is in grade 5, so she's getting into some fun things at school. This week the class paired off to meet a challenge: build a container to keep hot water hot. Cool!

The teams built their contraptions over the weekend, doubtless with varying degrees of rule interpretation (my daughter's involved HotHands hand warmers, which I would not have thought of), and the results were established with a side-by-side comparison. Someone (not my daughter) won. Kudos was achieved.

But this should not be the end of the exercise. So far, no-one has really learned anything. Stopping here is like grinding wheat but not making bread. Or making dough, but not baking it. Or baking it, but not making it into toast, buttering it, and covering it in Marmite...

Great, now I'm hungry.

The rest of the exercise

How could this experiment be improved?

For starters, there was a critical component missing: control. Adding a vacuum flask at one end, and an uninsulated beaker at the other would have set some useful benchmarks.

There was a piece missing from the end too: analysis. A teardown of the winning and losing efforts would have been quite instructive. Followed by a conversation about the relative merits of different insulators, say. I can even imagine building on the experience. How about a light introduction to thermodynamic theory, or a stab at simple numerical modeling? Or a design contest? Or a marketing plan?

But most important missing piece of all, the secret weapon of learning, is iteration. The crucial next step is to send the class off to do it again, better this time. The goal: to beat the best previous attempt, perhaps even to beat the vacuum flask. The reward: $20k in seed funding and a retail distribution deal. Or a house point for Griffindor.

Einmal ist keinmal, as they say in Germany: Once is never. What can you iterate today?