\begin{definition}[Definition:Independent Shocks]
Let $M$ be a stochastic model which describes a time series in which adjacent observations are highly dependent.
Then $M$ may be able to be modelled by a time series whose elements are of the form:
:$\map z t = \map {z_d} t + \map {z_r} t$
where:
:$\map {z_d} t$ has a deterministic model
:$\map {z_r} t$ has a stochastic model which consists of a sequence of independent random variables from a specified probability distribution (usually a white noise process).
The terms of the sequence $\sequence {z_r}$ are known as '''independent shocks'''.
\end{definition}