10 Mar 2004
CS 3243 - Bayesian Networks
9
Constructing
Bayesian networks
n1. Choose an ordering of variables X1, …
,Xn
n2. For i = 1 to n
nadd Xi to the
network
nselect parents from X1, … ,Xi-1 such that
P (Xi |
Parents(Xi)) = P (Xi | X1, ... Xi-1)
This choice of parents
guarantees:
P (X1, … ,Xn)
= πi =1 P (Xi | X1, … , Xi-1)
(chain rule)
(chain rule)
= πi =1P (Xi | Parents(Xi))
(by construction)
(by construction)
n
n