As a journeyman researcher in expert reasoning, Rugg ferreted out errors and unseen problems in various industrial and office management cases. It was good work for a human-error psychologist, but he wanted to tackle bigger issues. If experts were making mistakes in doctor's offices and factories, he reasoned, they were making them in labs, too. "My gut feeling is that a lot of research involves pattern-matching," Rugg says. "It guides what is investigated and then the design of the study."

Sometime in 1996, while having lunch with colleague Joanne Hyde, it occurred to Rugg that he could pull together all the tools psychologists use - elicitation techniques, the vast literature on human error, decisionmaking models, formal logic and reasoning - to create a novel form of problem-solving: a scientific method to verify the methods of science.

The verifier method boils down to seven steps:

1. amass knowledge of a discipline through interviews and reading
2. determine whether critical expertise has yet to be applied in the field
3. look for bias and mistakenly held assumptions in the research
4. analyze jargon to uncover differing definitions of key terms
5. check for classic mistakes using human-error tools
6. follow the errors as they ripple through underlying assumptions
7. suggest new avenues for research that emerge from steps one through six.