In probability theory, an elementary event (also called an atomic event or sample point) is an event which contains only a single outcome in the sample space. Using set theory terminology, an elementary event is a singleton. Elementary events and their corresponding outcomes are often written interchangeably for simplicity, as such an event corresponding to precisely one outcome.
|Part of a series on statistics|
The following are examples of elementary events:
- All sets where if objects are being counted and the sample space is (the natural numbers).
- if a coin is tossed twice. H stands for heads and T for tails.
- All sets where is a real number. Here is a random variable with a normal distribution and This example shows that, because the probability of each elementary event is zero, the probabilities assigned to elementary events do not determine a continuous probability distribution.