Monday, March 10, 2014

Diagnosis Bias

"We tend to accept the diagnosis of a problem that fits our set of favorite solutions even when better alternatives are present."

In a short article entitled "Why Good Thoughts Block Better Ones" in the March issue of Scientific American M. Bilalic and P. McLeod talk about "confirmation bias."

They describe "the human brain's dogged tendency to stick with a familiar solution to a problem - the one that first comes to mind - and to ignore alternatives." 

Admitting that this thinking can be very useful, they describe the situation of a person peeling garlic. "Once you have hit on a successful method ... there is no point in trying an array of different techniques every time you need to peel garlic."

They caution us saying, "The trouble with this cognitive shortcut, however, is that it sometimes blinds people to more efficient or appropriate solutions than the ones they already know."

Can we learn to reduce our tendency to slip into confirmation bias? They say that the more expertise on has in their field ... the more immune they are to [confirmation] bias.

Bilalic and McLeod caution us saying, "But no one is completely impervious." Continuing, they say, "Remember that if you already think you know the answer, you will not judge the evidence objectively. Instead you will notice evidence that supports the opinion you already hold, evaluate it as stronger than it really is and find it more memorable than evidence that does not support your view."

I am constantly challenged to be objective. To use measurable outcomes in evaluating the success of a calf enterprise: mortality, morbidity, growth rates. To use quantified measures for assessing the quality of inputs - bacteria plate counts, temperatures, parts per million, hours, weights. Even then, in the back of my mind I need to maintain a little nagging thought, "How else might this [whatever is not good] be explained."

If you want to have fun and can pronounce German, this confirmation bias has the technical name, Einstellung effect.

Merium Bilalic and Peter McLeod, "Why good thoughts block better ones." Scientific American Vol 310:No. 3, pp75-79, March, 2014.

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