Interesting article in this week's The New Yorker about how doctors think / make decisions. What's the Trouble, a medical dispatch by Jerome Groopman is subtitled "How Doctors Think." I'd say it's also about how they make decisions, and specifically three kinds of thinking that lead to bad decisions on their part. Malcolm Gladwell covered this a bit in Blink : the power of thinking without thinking, but this is a personal essay on topic.
Groopman describes three kinds of thinking that adversely affect doctors' decision making, with three different anecdotes.
1. Representativeness errors -- you believe what you see and "fail to consider possibilities" that contradict your mental template. The opposite of Occam's razor?
2. Availability errors -- when you see six patients in a row with the flu, and the seventh presents with similar symptoms, you're more apt to diagnose the seventh with the flu too (kind of like word priming, I'd guess); first described by Tversky & Kahneman, in Availability: A heuristic for judging frequency and probability. Cognitive Psychology in 1973. (wikipedia on availability)
3. Personal feelings for a patient -- The good Dr. Groopman admits to missing a diagnosis because he was reluctant to subject his "favorite patient on the ward" to an extensive (and buttocks) exam.
This is interesting for the medical profession, but it has (less dire) implications for librarians too -- I know I make assumptions at the reference desk which color the questions I ask. Sometimes I guess right, but not always, and then I have to backtrack, and occasionally start over.
Finally, Groopman refers to Achieving quality in clinical decision making: cognitive strategies and detection of bias, by Pat Croskerry, published in the 2002 Academic Emergency Medicine for more info.