I have been reading "How Doctors Think" by Jerome Groopman. It is one of two books with the same title. Basically, reading this will make you scared to go to the doctor as doctors are human and make lousy decisions, just like all the rest of us. He has a good chapter titled "The Uncertainty of the Expert" which focuses on my favorite topic, decision making with uncertain information. All of Groopman's comments come from cognitive psychology and apply to business and technical decisions as well.

The key point in the chapter is captured in one sentence about half way in: "Physicians, like everyone else, display certain psychological characteristics when they act in the face of uncertainty". Uncertainty arises from 1) incomplete mastery of the available knowledge, 2) limitations of the knowledge, 3) difficulty distinguishing between the 1 and 2, and 4) (he leaves this one out) the variability of the nature of things.

In the face of uncertainty we all tend to:

1. Focus on the positive rather than the negative (except engineers who are pessimists by nature).
2. Ignore uncertainty. This is very evident in how we all talk about technical issue in terms of single values. Luckily we have terms like "about", "near to"
3. Go with what's been done before even if it is based on an unknown and unproven orthodoxy. Of course risk aversion is good and in medicine often leads to the correct diagnosis, whenever the problem is by-the-books. However, in business, technology this aversion can lead to being swamped by the competition.
4. Have a confirmation bias. This means that we look for support for our favorite alternative or hypothesis, at the expense of work on other possible options and discounting the negative (see item 1).

In the medical profession these characteristics are supported by the lack of time, risk aversion and an old-boys-club attitude. It is interesting watching the decision making on the TV program House. Here an arrogant, troubled doctor who hates the establishment diagnoses rare conditions and displays items 1, 2, and 3. He is really good at #3. But, most of us are.