#122 - The square root of a jam jar!

10 Sep 26

There used to be a saying about certain Engineers: they could work out the square root of a jam jar, but couldn't work out how to remove the lid. It was an insult, and a fair one in some cases. It also points at a gap that never fully closed, and still hasn't.

Trial Brief

Being able to solve a problem on paper and being able to solve it in the real world are not the same skill, and the Engineering profession has been quietly aware of this divide for decades, even if it rarely says so directly. The question isn't whether the gap between theory and application exists, it's how you actually bridge it.

Trial Execution

I first heard the accusation as an apprentice. My engineering apprenticeship in the Royal Navy in the mid-1980s was an intensive technical course of study, and it led to fast-track promotion to non-commissioned officer. Being fast-tracked came with a price. Those on the slower path had a phrase for it: we could work out the square root of a jam jar, but we couldn't work out how to get the lid off. It was a jab at exam performance without practical follow-through, and however much it stung at the time, it wasn't entirely unfair.

Years later, after I'd graduated from university with an engineering degree, I heard an almost identical accusation aimed at a different group. Graduates who had never done 'real engineering', who had never got their hands dirty or grease under their nails, faced the same charge but using different words. Two very different training paths, a decade or more apart, with the same fault-line running through both: Engineers who were clearly excellent on theory, calculator in hand, but far less sure-footed once they were standing in front of a real fault, in a real operational environment, with a real decision to make.

Trial Findings

What both accusations were really pointing at wasn't a knowledge gap. Both sets of Engineers, apprentices and graduates alike, absolutely knew their theory for sure. What was missing was something theory doesn't teach on its own: common sense, intuition, experience and the judgement that only comes from having been wrong a few times in conditions that mattered.

That distinction matters because it changes where the fix has to happen. If the problem was purely a knowledge gap, then more study would close it. It doesn't, because the gap isn't in what these Engineers know, it's in what they've had the chance to practise. Judgement isn't something you can derive from first principles under exam conditions. It's built the same way any practical skill is built: through repeated exposure to real situations, ideally with someone more experienced who is close enough to catch you before a mistake becomes serious. But far enough away to let you actually make the call yourself.

Bridging that gap, in practice, tends to come down to a small number of deliberate choices rather than one big fix. It comes from pairing strong theoretical performers with experienced practitioners early, not after they've already proven themselves on paper. Or by giving them real problems with real consequences sooner rather than later, even in a controlled or supervised form, rather than protecting them from anything ambiguous until they're deemed 'ready'. Additionally it comes from treating early mistakes as the expected cost of building judgement, not as evidence the person shouldn't have been trusted with the problem in the first place. None of that is rocket science, it's simply choosing deliberately to expose theoretical strength to practical reality early enough for the two to actually meet.

The Common Thread

The 'jam jar' and the 'never got their hands dirty' accusations are the same complaint, separated by a training path and a decade. Theoretical strength and practical judgement don't arrive together automatically, however good the theory is. They have to be deliberately brought together, through exposure, mentorship and the willingness to let capable people make real mistakes early, while the stakes are still manageable.

Trial Sign-off

One practical action

Identify one strong theoretical performer in your team who hasn't yet had much exposure to messy, real-world problem-solving. This week, put them in front of one, with an experienced practitioner close enough to support them but far enough away to let them own the decision.

One question for reflection

Where in your organisation are you still protecting capable people from real, ambiguous problems in the name of readiness and what judgement are they missing out on building as a result?

Have a great week!

Steve

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