Simpson’s Paradox is one of the classic paradoxes, made famous by the UC Berkeley’s experience,

In 1973, the admission rate for men and women were noted to be very different for UC Berkeley. The admission rate for men was 44% and for women was 35%, The difference was statistically different. Continue reading “Simpson’s Paradox” →

Lord’s Paradox, which is a special instance of Simpson’s Paradox, is as follows (excerpted from Lord’s original paper): Continue reading “Lord’s Paradox” →

In 1990, New York City closed 42nd Street in observance of Earth Day (1).

The 42nd Street is a major thoroughfare, and its closure was expected by many to be a disaster. Manhattan’s traffic is bad enough on an ordinary day: surely the closure of a major artery could only make it worse.

To everyone’s surprise, except certain mathematicians, the closure significantly improved traffic that Continue reading “Braess’s Paradox” →

Small Sample Size Illusion is an illusion that will eventually make it into my next iteration of the cognitive optical illusions slide set, but in the meanwhile, I am posting it on the blog.

Let me start with an example borrowed from Howard Wainer’s article in the American Scientist, “The Most Dangerous Equation.”  If you were Continue reading “Small Sample Size Paradox” →

In the Feb 23, 2011 issue of JAMA, there is an article that discusses a little-recognized but important paradox.  I think it’s as important as Simpson’s Paradox, which I plan to write about in a future blog.  However, unlike Simpson’s Paradox, which is widely appreciated, Dahabreh’s Paradox is not well-recognized. Continue reading “Dahabreh’s Paradox” →