Estimating the probability for an event can be done in two ways: 1) Using historical data about the frequency of the event. 2) Using direct knowledge about the mechanisms that can cause the event.
Examples: - The probability for lung cancer as death cause for a smoker can be estimated from the death rate of other smokers (approach 1). - The probability for getting a 6 when casting a die can be calculated from our knowledge about the geometry of the die and its environment (approach 2). Of course, the probability for getting a 6 can be estimated by looking at historical casts of dice, and lung cancer might be calculated from our knowledge about the lungs, the immune system, the tobacco smoke etc. The latter would be quite cumbersome since it would be very complicated. What I wonder is, are these two approaches, 1 and 2 above, really distinctly different? Are there other approaches? What are the implications of using either? What if the two approaches yield different estimates for the same event? How come that the same phenomena, the probability, can be deduced by two so very different approaches? . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
