Agree. From the DK article graph it is not possible to separate the cases
1. Average self assessment coincides with true skill, but variance increases with low skill.
2. Average self assessment is biased, and the bias is positive when you are unskilled and negative when you're highly skilled.
These two situations would create indistinguishable DK-graphs. I don't understand how anyone can be sure on either (1) or (2) after seeing one instance of such a graph.
As I see it, the only way out for "DK positivists" is to say that the DK hypothesis is unrelated to the truth values of (1) and (2). Or, that there is other evidence making DK convincing.
1. Average self assessment coincides with true skill, but variance increases with low skill.
2. Average self assessment is biased, and the bias is positive when you are unskilled and negative when you're highly skilled.
These two situations would create indistinguishable DK-graphs. I don't understand how anyone can be sure on either (1) or (2) after seeing one instance of such a graph.
As I see it, the only way out for "DK positivists" is to say that the DK hypothesis is unrelated to the truth values of (1) and (2). Or, that there is other evidence making DK convincing.
Neither seems very plausible!