Expected distortion
= Expected distortion
{title2=$\mathbb E[d(X,\widehat X)]$}
<Expected distortion> is the <expectation> of the reconstruction cost under the joint <probability distribution> of $X$ and $\widehat X$. It weights common source outcomes more strongly than rare ones. A bound on <expected distortion> is therefore different from a bound on the cost for every input, or on the <probability> of exceeding a specified cost.