Chance News 43
Second thoughts about test of racial bias
In bias test, shades of gray. John Tierney, The New York Times, November 17, 2008.
A recent study showed racial bias in the way that doctors treat their patients. Or maybe not. At the heart of the study of racial bias is the I.A.T. (Implicit Association Test). This is a computerized test that measures how quickly you associate good words with faces of white subjects, bad words with faces of black subjects. If you do this more rapidly than when you associate bad words with faces of white subjects and good words with the faces of black subjects, then you have a racial bias.
The test is widely used in research, and some critics acknowledge that it’s a useful tool for detecting unconscious attitudes and studying cognitive processes. But they say it’s misleading for I.A.T. researchers to give individuals ratings like “slight,” “moderate” or “strong” — and advice on dealing with their bias — when there isn’t even that much consistency in the same person’s scores if the test is taken again.
The researchers who have developed the I.A.T. argue that the test is very useful.
In a new a meta-analysis of more than 100 studies, Dr. Greenwald, Dr. Banaji and fellow psychologists conclude that scores on I.A.T. reliably predict people’s behavior and attitudes, and that the test is a better predictor of interracial behavior than self-description.
There have been calls to try to mediate the dispute between researchers who developed the I.A.T. and those who criticize it, but these have not led to anything yet.
After all the mutual invective in the I.A.T. debate, maybe it’s unrealistic to expect the two sides to collaborate. But these social scientists are supposed to be experts in overcoming bias and promoting social harmony. If they can’t figure out how to get along with their own colleagues, how seriously should we take their advice for everyone else?
Submitted by Steve Simon
1. What is the technical term for "lack of consistency" in results if the test is taken again? Why is this a problem?
2. What is the technical term for the ability of a test to "reliably predict people's behavior and attitudes"? Why is this important?
3. Take the test yourself at implicit.harvard.edu. Do you think it accurately reflects your personal prejudices (or lack thereof)? How else might you measure your personal prejudices?
BBC 4 discusses probability
The BBC4 has a series of programs wich are described as follows: "The big ideas which form the intellectual agenda of our age are illuminated by some of the best minds. Melvyn Bragg and three guests investigate the history".
A recent program discussed probability. The guests were Marcus du Sautoy from Oxford University,Colva Roney Dougal from St. Andrews University, and Ian Stewart from Warrack University. None of these are probabilists but Ian Stewart had discussed probability in several of his very nice books and discussed probability in his popular lectures.
The discussion is quite good. Of course they have to include the birthday problem and the Monty Hall problem but towards the end they discuss more serious probability contributions such as Bolzmanns's work in statistical physics and the role of probability in quantum theory and here of course they include Einstein's famous God does not play dice. It would to have more time to spend of some of the more interesting topics. However you, your students, and your Aunt Mary or Uncle George should enjoy this discussion.
Read the comments about the program here and see what you think of the audiance reaction.
Heaven for the Godless?
New York Times, December 26, 2008
Op Ed, By Charles M. Blow