Sunday, November 21, 2010

[Book] Hot hand fallacy


 Hot hand fallacy states that if performing well in last consecutive trials, a person might perform well in the next trials. In fact, the streak (of well-performance) may just be because of pure chance. If this is the case, the results in the few consecutive trials infer nothing about the next trials.


Hot hand fallacy is perceived in various fields such as sport or business. We usually judge people (e.g., basketball players or companies) by statistics. But we usually misled by a hot hand fallacy. When a good player makes several baskets consecutively, we tend to think that his hand is “hot”, and that his teammates should give him the ball. So if an average player makes several baskets consecutively, does is mean that his is better than a good player? No, because if he is better, his statistics would have been better. The fact that he makes a lot of baskets consecutively implies that he might miss a lot of baskets too. We just don’t know when it will happen.

Saturday, November 13, 2010

[Book] People, Perception, Perfection, and Randomness


 Perfection requires perfect perception. It is hard to achieve perfection, since the data we perceives is rarely perfect. So how do we determine whether what we perceive is true. In a more technical term, how do we accept or reject the hypothesis based on what we perceived? In this respect, statisticians resort to "Significant Testing" in order to make decision based on observations.

"Human perception is very narrow. There is only about 1 degree of visual angle around the retina center which has high resolution. Outside this region, the resolution drops off sharply. Therefore, we tend to move our eyes a lot to compensate for the narrow visual area."