uncertainty measure

Given uncertainty of sensors and uncertan reasoning we often want to have some sort of idea the level of certainty of the results we are seeing. Examples in statistics include the {[standard deviation}} or confidence intervals, and there are parallels in AI algorithms. This may be used in further processing, for example weighing more highly more ceryain values, or for visualising uncertainty, for exampel, using error bars of graphs. Of course any such meausres of uncertainty is itself usually uncertain!