"Our own recent work shows that, yes, you need experts to spot experts," [David Dunning] said. "Everyone can spot the poor performer, but often spotting the best performers is beyond the competence of the group. That said, spotting an expert outside of one’s field is a task one can become better at. And that’s important, given just how much information, good and bad, is not available to people. For example, is the expert associated with a university (a good sign) or some....