10 Mar 2004
CS 3243 - Uncertainty
17
Normalization
nDenominator can be viewed as a normalization constant α
P(Cavity | toothache) = α · P(Cavity, toothache)
= α · [P(Cavity, toothache, catch) + P(Cavity, toothache, Øcatch)]
= α · [<0.108,
0.016> + <0.012, 0.064>]
= α · <0.12, 0.08>
= <0.6, 0.4>
General idea: compute
distribution on query variable by fixing evidence variables and summing over hidden variables