Ron Zeno has posted a summary of and a few comments on Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments (Justin Kruger and David Dunning – Journal of Personality and Social Psychology).

People are generally pretty bad at estimating their own performances (the people who are worst at a skill grossly overestimate their ability because they don’t know enough about the skill to recognize their own mistakes) and those who are best tend to underestimate their ability (probably because they know enough about the subject that they’re aware of how much they don’t know, and they can more easily spot their own mistakes). —Critical Thinking, Human FactorsRon’s Ramblings)