Relative
Frequency Definitions
The exercise of flipping coins or rolling dice illustrates
the "relative frequency" view of probability. Any specific result is an
"outcome," like rolling the pair (1,6). The six pairs that total seven on the
faces are collectively an "event." We see that the probability of the event "7"
is 1/6, whereas the probability of the outcome (1,6) is 1/36. All the 36
possible outcomes are a "set," the event being a subset. "Population" is another word for "set." "Opportunity
space" or sometimes "space" is used interchangeably with population, set,
subset, and event. Context is required to clarify the usage.
The relative frequency interpretation of probability leads to the
following equation as the general definition of probability:
p(A) = N(A)/N(M)
where p(A) is
probability of outcome (or event) A,
N(A) = number of times A occurs in the population, and N(M) = number of members in the population.