More on Learning Bayes Nets

EM algorithm can also be used. Repeatedly:

1. Calculate probabilities of unobserved variables, assuming 3#3
2. Calculate new 183#183 to maximize 191#191 where 5#5 now includes both observed and (calculated probabilities of) unobserved variables

When structure unknown...

• Algorithms use greedy search to add/substract edges and nodes
• Active research topic