The strict academic definition hasn’t followed the colloquial usage for a long time. Maybe ever:

If a specific novice is over-confident and out of their depth, we say “Dunning-Kruger”

If a specific is under-confident and performing better than their self-estimate, that’s not commonly considered Dunning Kruger, in the colloquial use. It’s called imposter syndrome, or not labeled at all.

The researchers aren’t really disagreeing with that. They found that novices had a wider range of self-estimates of their performance than experienced people. So in the novice group you were more likely to find someone who was grossly over-confident in their abilities, but you also found people who underestimated themselves.

> instead showed that both experts and novices underestimate and overestimate their skills with the same frequency. “It’s just that experts do that over a narrower range,” he wrote to me.

Which doesn’t precisely contradict the idea that among novices you can find people who overestimate their skills. Which is how it’s commonly used.

So I can believe it’s a statistical wash when averaging across all subjects. But I never considered the common use of Dunning-Kruger to be applied to averaged groups of people. It was always brought out for those outliers on the long tail of the novice grout who thought didn’t even know what they didn’t know.

I think people overlook the natural experience of Dunning-Kruger we all have.

You think you are good at chess because you win against your neighbour, then eventually a class mate absolutely embarrasses you multiple times and you realize there is a whole world you don't know, and before now you didn't know that world existed. Then you eventually beat your classmate before getting whomped by the beginner in the chess club and the whole cycle happens again. After this happens a few times, you should begin to find each time less surprising than the last.

To me this is the essence of DK and not really something to be proven/disproven by maths. You don't know what you don't know, and it takes some learning before you are wise enough to realize there are unknown unknowns.

> instead showed that both experts and novices underestimate and overestimate their skills with the same frequency. “It’s just that experts do that over a narrower range,” he wrote to me.

I think this is trying too hard on the researcher's part... if the data were reinterpreted such that small estimation errors are considered correct then the effect would reappear.

> The strict academic definition hasn’t followed the colloquial usage for a long time. Maybe ever:

This is my understanding as well, and as I recall the results of the research were also more nuanced than most people seem to indicate. So not only were the novices with a wider range of self-estimates, the average result of those perceived scores was still below the experts. So it was never that low performers thought they were experts (although this may show up in the raw results with some portion of the population tests), just that on average they perceived their performance to be better than it actually was. And the high competence group while overestimating their results, still thought they'd do better than the low performers.

You've hit the nail on the head, it's a conditional defenition, rather than an absolute one.