In a large number of hypothetical repetitions of the planned trial, the proportion of trials in which the event would occur. The chance that a given event will occur.
Probability is how the chance of a particular outcome is quantified.
One can imagine that a particular outcome is randomly drawn from a population, Suppose that Y is a binary outcome, and it is known that One paradigm for this is to have a bag of 4 balls of which 3 balls are marked 0 and 1 ball is marked 1 . Well, two outcomes are going to work differently. The Bag of Balls example generalizes to the general idea of probability. Only a certain subset of the data are observed, of which all the data are in a Bag of Balls . The experimental design determines the constituents in the Bag of Balls .