Does the 1999 paper by Kruger and Dunning "Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments" reliably prove that incompetents have a consistently higher self-appraisal than competents?
I'm accepting that the gap between self-appraisal and reality is greater for incompetents than for competents (the paper discusses the potential for a regression effect in their statistical analysis), and that most people think they are above average ("Illusory superiority" or the "Lake Woebegone effect"), but the paper says that more than that is going on. It describes Charles Darwin as saying
"ignorance more frequently begets confidence than does knowledge"
and this study has been cited by the general public:
@gilles that's kind of intentional; we basically don't want these users. en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect – Jeff Atwood♦ May 15 at 20:03
(As far as I can tell, Atwood was implying that incompetent users are more likely to think that there's an error on the Stack Exchange servers than competent users)
Has the methodological rigour, and the relevance, of the paper been generally accepted?
Also, is their claim that incompetents have a higher self-appraisal than competents been treated by the scientific community as strongly confirmed, or is there still doubt about this claim within the mainstream?
If the claims are true, how come there wasn't a negative correlation between actual ability and perceived ability in figures 1, 3 and 4 in the 1999 paper? (PDF)