Definition: interpretation or estimate of probability as the long-run frequency of the occurrence of an event as estimated by historical observation or experimental trials Sample Usage: (1) Based on empirical evidence from repeated experimental trials, the frequentist probability of getting a three when rolling a fair six-sided die is 1/6 or 16.7%. (2) Based on historical evidence, scientists can provide a frequentist probability of experiencing a category 5 hurricane in a given year. Annotation: (1) Within the frequentist probability interpretation, precise estimation of new or rarely occurring events, such as the probability of a catastrophic terrorist attack, is generally not possible. (2) Frequentist probabilities generally do not incorporate -degree of belief information, such as certain types of intelligence information. See Also: probability, Bayesian probability, and subjective probability