Subjective Probability

Probability may be determined by a personal statement of how likely an outcome is in a single trial or repetition of the same experiment.

Since subjective probabilities are based on personal judgement, they are peculiar to the individual making the decision. The probability statement depends upon the individual's experience and his familiarity with the facts of the case. Two decision makers with the same amount of information would make different subjective probability estimates of the occurrence of a particular event.

Example 

An expert analyst of share prices may give his judgement that the price of ACC shares has a 20% probability of increase i.e., by Rs.500 or more in the next two months, a 60% probability of increase i.e., by less than Rs.500 in the next two months and a 20% probability of remaining unchanged or registering a slight fall.