Dunning-Kruger Effect

Wikipedia says it well…

The Dunning–Kruger effect is a cognitive bias in which unskilled people make poor decisions and reach erroneous conclusions, but their incompetence denies them the metacognitive ability to realize their mistakes.[1] The unskilled therefore suffer from illusory superiority, rating their own ability as above average, much higher than it actually is, while the highly skilled underrate their abilities, suffering from illusory inferiority. This leads to the situation in which less competent people rate their own ability higher than more competent people. It also explains why actual competence may weaken self-confidence.

Remind me to dig out the KL ratio thing that Simon Hoggart talked about one time…