Hutchinson offers several recommendations. If you are dealing with an issue about which there is some slight uncertainty, always assume at least a 20 percent chance that you are wrong. This, Hutchinson notes, has two beneficial effects. First, on average, this will be closer to reality. Carefully examine the areas of your expertise and find the boundaries of your knowledge.
Research shows that people who have expertise in a certain area tend to over-generalize that.
The fact that someone is an expert in one industry does not imply that that knowledge will extend to other areas. As people move beyond their immediate area of expertise, their ability drops off sharply but their confidence does not. The disconnect between expertise and confidence, paradoxically, puts experts at risk. Look for base rates. Each decision and situation is different.