"A friend brought me to where the horses were being judged," recalls Klein. "She tried to explain the characteristics of a good horse. Over the years, she had learned a lot about these animals, and she could see things that I couldn't see. She had accumulated all of this knowledge, but it wasn't a burden. She carried it all so easily. And I remember thinking, That's expertise. That's how it gets used.

"We sometimes think that experts are weighed down by information, by facts, by memories -- that they make decisions slowly because they must search through so much data. But in fact, we've got it backward. The accumulation of experience does not weigh people down -- it lightens them up. It makes them fast."

Bill Breen (bbreen@fastcompany.com) is a senior editor at Fast Company. We trust his instincts. Contact Gary Klein by email (gary@klein-inc.com), or learn more about Klein Associates Inc. on the Web (www.decisionmaking.com).

Sidebar: Premortems: Fix Problems Before They Happen

One of the prime tools used in rapid decision making is mental simulation -- the ability to evaluate a course of action by imagining how it may unfold and may ultimately play out. At Klein Associates Inc., work groups use a form of mental simulation called a "premortem" to discover a new project's hidden flaws.

A premortem works like this: When a team gathers to kick off a new project, people conclude the meeting by pretending to gaze into a crystal ball. They look six months into the future, and the news is not good. Despite their hopes, the project has failed. Then team members take three minutes to run a mental simulation. They write down why they think their work derailed. All sorts of reasons emerge.

"People might say that I pushed the project in my own direction and created complications," says Gary Klein, the company's founder and its chief scientist. "Someone else will say that the project was too ambitious -- that we should have streamlined it. I might say that the two people who led the project had other big responsibilities, and they blew the deadline."

The group's comments are unusually candid. The reason, says Klein, is that the conversation's context is radically different from a critique. The entire focus is on trying to understand why the project failed. By looking six months into the future, people feel secure enough to say what they really think. Then they snap back to the present. Each comment is recorded, so that all of the members know the potential speed bumps before they go forward.

The exercise helps people work smarter. It keeps them from getting overconfident. And it seems to make sense. "With a postmortem, everything you learn is after the fact," says Klein. "With a premortem, we give ourselves a chance to uncover problems and then fix them in real time, as the project unfolds."