Modular Belief Updates and Confusion about Measures of Certainty in
  Artificial Intelligence Research
  Over the last decade, there has been growing interest in the use or measures
or change in belief for reasoning with uncertainty in artificial intelligence
research. An important characteristic of several methodologies that reason with
changes in belief or belief updates, is a property that we term modularity. We
call updates that satisfy this property modular updates. Whereas probabilistic
measures of belief update - which satisfy the modularity property were first
discovered in the nineteenth century, knowledge and discussion of these
quantities remains obscure in artificial intelligence research. We define
modular updates and discuss their inappropriate use in two influential expert
systems.
