### Stationary Stochastic Process

**Definition: **
We define a *stationary* stochastic process
,
as a stochastic process consisting of
*identically distributed* random variables
. In
particular, all statistical measures are *time-invariant*.

When a stochastic process is stationary, we may measure statistical
features by *averaging over time*. Examples below include the
sample mean and sample variance.

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Expected Value

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Stochastic Process