Lesson 1: To Err Is Human  Latent errors are defects in the design and organization of processes and systems that can lead to failures and errors. Latent errors, first suggested by psychology professor James Reason, are often unrecognized or just become accepted aspects of the work. Latent errors lead to active errors, whose effects are felt immediately. To prevent errors, you need to design processes that make it easy for people to do things right, and hard to do things wrong. Lesson 2: Responding to Error  Blaming and punishing an individual does not address the underlying issues that led to an event and does not prevent a recurrence. Only about 5 percent of medical harm is caused by incompetent or poorly intended care.  In contrast, 95 percent of medical harm involves conscientious, competent individuals involved in circumstances that lead to a catastrophic result.The Josie King story is an example of responding to error – and, in this case, tragedy – without blaming or seeking punishment.Although blaming and punishing individuals for errors are not appropriate responses, individuals should still be accountable for their actions