‘Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self Assessments’, by Justin Kruger and David Dunning. They noted that people who are incompetent suffer a dual burden: not only are they incompetent, but they may also be too incompetent to assay their own incompetence, because the skills which underlie an ability to make a correct judgement are the same as the skills required to recognise a correct judgement.