Rev. Thomas Bayes and intelligent estimation of probability of an event, given partial iinformation

Submitted by Howard T, Hermann (United States), Jun 14, 2006 at 18:02

Profiling is no more or no less than the estimation of the likelihood of an event being present given only partial information about the event under consideration (here the likelhood of a terrorist being present). Reverend Bayes (early 18th century) recognized that the known past history associated with a partial observation (prior probabilities) effected the likelhood that a given partial observation actually was a correct inference. He calculated statistically how this could be done.

Basically, it is a model of how our human brain reacts to events it perceives. If one sees a writhing snake-like object, the likelhood that it is a snake is estimated on the basis of how often in the past was a visual pattern similar to that invariably accompanied by the actuality of a snake. The field is called Bayesian Statistics. Police officers must use intelligent estimation of probabilities or they will be killed. One would never query a five year old child as a likely terrorist candidate whose intent it was to harm society. Politically 'correct' moralists object to anyone being discriminated just because they appear to be a member of a potentially dangerous group. However, it becomes the group's responsibility to reduce the likelihood of their members being associated with threatening behavior if they are to reduce these inferences..

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