Setting: learning parameters of Bayesian Network (BN) with missing data.
Question: suppose I am in the M-step, and that in the complete data there are no examples for one class. In this case, how can I update the conditional probability for that specific class?
I understand that the question is quite vague. Thus, please see slide 15: how can I get $p(X_3=2 | X_2=1)$ if there are no examples in the complete data?