The utility of formal protocols, according to organizational experts, varies with the nature of the activity—some activities are highly systemized, like engineering, and others dependent on the judgment and personality of the individual. Spontaneity and imagination are important in many jobs, including teaching and management of all kinds. Dr. Gawande seems to assume that formal checklists will be an unalloyed benefit. But most people can think of only one thing at once: If they're thinking about a checklist, they may not be focusing on solving the problem at hand. Many tasks require trial and error—not checklists designed to avoid error. "Hell, there ain't no rules around here," Thomas Edison famously said. "We're trying to accomplish something."