Anders and I addressed this question somewhat in Peak, but there is much more to learn about it: In medicine, how do you tell what good performance is? From what I can tell, it’s easiest to tell in areas like surgery where mistakes are often noticeable quite quickly. But in areas like imaging, a doctor may have to wait a long time to find out — or may never find out — whether a particular reading was right or wrong. I’d like to hear from people in the medical field what sorts of objective measures exist for determining how good a doctor’s performance is and for identifying strengths and weaknesses. Such measures are crucial to providing the feedback that allows people to improve. What mechanisms exist for providing such feedback in medicine?