What does it mean to use subjective probabilities?
The classical and relative frequency methods of assigning probabilities cannot always be used, especially in circumstances where there is no way to collect data, or to determine the number of events. What for example, is the probability that life exists on a planet circling the nearest star, Alpha Centauri? In such circumstances, one must come up with a subjective opinion; that is, one must use experience, intuition, or a hunch to arrive at a value. Of course, the value will be subjective, and different people can be expected to assign different values to the same event.
