About Updating
  Survey of several forms of updating, with a practical illustrative example.
We study several updating (conditioning) schemes that emerge naturally from a
common scenarion to provide some insights into their meaning. Updating is a
subtle operation and there is no single method, no single 'good' rule. The
choice of the appropriate rule must always be given due consideration. Planchet
(1989) presents a mathematical survey of many rules. We focus on the practical
meaning of these rules. After summarizing the several rules for conditioning,
we present an illustrative example in which the various forms of conditioning
can be explained.
