Bayesian networks: A simple, graphical notation for conditional independence assertions and hence for compact specification of full joint distributions Syntax:
P(Xi|Parents(Xi))
In the simplest case, conditional distribution represented as a conditional probability table (CPT) giving the distribution over Xi for each combination of parent values
Example: Topology of network encodes conditional independence assertions:
Weather is independent of the other variables
Toothache and Catch are conditionally independent given Cavity
Example: I’m at work, neighbor John calls to say my alarm is ringing, but neighbor Mary doesn’t call. Sometimes it’s set off by minor earthquakes. Is there a burglar?
Variables: Burglar, Earthquake, Alarm, JohnCalls, MaryCalls Network topology reflects “causal” knowledge: