One of the most exciting things about Bayes nets is that they can be
used to put discussions about causality on a solid mathematical basis.
One very interesting question is: can we distinguish causation from mere
correlation? The answer is "sometimes",
but you need to measure the relationships between at least
three variables; the intution is that one of the variables acts
as a "virtual control" for the relationship between the other two,
so we don't always need to do experiments to infer causality.
See the following books for details.
- "Causality: Models,
Reasoning and Inference",
Judea Pearl, 2000, Cambridge University Press.
- "Causation,
Prediction and Search", Spirtes, Glymour and
Scheines, 2001 (2nd edition), MIT Press.
- "Cause
and Correlation in Biology", Bill Shipley, 2000,
Cambridge University Press.
- "Computation, Causation and Discovery", Glymour and Cooper (eds),
1999, MIT Press.