topic Re: Interpretation bayesian network graph in SAS EM in SAS Data Science

Interpretation bayesian network graph in SAS EM

Bruno_F — Sun, 28 Jan 2018 11:23:27 GMT

Hi,

I try to use the HPBNET node in SAS EM in order to explain a target variable from input variables. By using this node, i would like to know the links between input variables and the effects on my target variable.
I tested several BN structures but only my target variable is a parent in my graph..
Can someone explain to me why my target is always a child ? How is it possible to make predictions if there is no parent variable for my target variable ?

Thanks !

Bruno

Re: Interpretation bayesian network graph in SAS EM

WendyCzika — Mon, 29 Jan 2018 14:30:10 GMT

It depends on the structure of your network. With a Parent-child or Markov blanket structure, the inputs can be parents of the target. This paper has all the details and equations of how the predictions for a target are obtained from a Bayesian network: https://support.sas.com/resources/papers/proceedings17/SAS0474-2017.pdf

Re: Interpretation bayesian network graph in SAS EM

Bruno_F — Mon, 05 Feb 2018 16:36:58 GMT

Hello WendyCzika,

Thank you for your answer !

I built a Bayesian Network Model in order to explain a binary variable. Is it possible to compute a kind of "contribution" in order to know which input variable is the most contributive in my model to explain my target ?

Also, I picked up the Scoring code from my model but I don't understand the rules on it :

Can someone can explain to me what is compute in this rule (in red) because is not a probability..

else if _I28 = 1
then do;
_target_score_HPBNC1{1}+(-1.538266175076);
_target_score_HPBNC1{2}+(-0.241757117828);
end;

Best regards,

Bruno