Can “expert” training increase confidence while making judgments worse?

I came across more interesting research about possible “placebo effects” in decision making.  According to the two studies cited below, receiving formal training in lie detection (e.g. so that law enforcement officers are more likely to detect a untruthful statement by a suspect) has a curious effect.  The training greatly increases confidence of the experts in their own judgments even though it may decrease their performance at detecting lies.  Such placebo effects were a central topic of The Failure of Risk Management.  I’m including this in the second edition of How to Measure Anything as another example of how some methods (like formal training) may seem  to work and increase confidence of the users but, in reality, don’t work at all.

  • DePaulo, B. M., Charlton, K., Cooper, H., Lindsay, J.J., Muhlenbruck, L. “The accuracy-confidence correlation in the detection of deception” Personality and Social Psychology Review, 1(4) pp 346-357, 1997
  • Kassin, S.M., Fong, C.T. “I’m innocent!: Effect of training on judgments of truth and deception in the interrogation room” Law and Human Behavior, 23 pp 499-516, 1999

Thanks to my colleague Michael Gordon-Smith in Australia for sending me these citations.

Doug Hubbard

Still no evidence…

I get many emails about the validity of Risk Maps, Risk Scores and Risk Matrices in risk analysis.  I know there are a lot of passionate proponents of these methods (and many heavily-invested vendors) but there is still no evidence that such methods improve forecasts or decisions.

Read my skeptical look at many risk analysis methods in the OR/MS Today and Analytics articles (See the Articles page).  I compiled quite a lot of research in these articles and even more in my book that should lead any manager to be suspicious about whether the perceived effectiveness of these methods is real or imagined.

I’ve updated the upcoming second edition of How to Measure Anything with even more research in that vein.  Stay tuned and post your comments.

Doug Hubbard

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