Dear All
In Genie ,i use following procedure to built bayesian network(BN)
1. built model
2. match model and data with EM algorithm to learn Conditional Probability Table(CPT)
then i get model with CPT,
but some probability value in CPT is 0.5
Is this because of no related data , so EM algorithm cant learning probability?
Kind Regards,
Wei
Probability of 0.5
Re: Probability of 0.5
There could be several reasons, but no data is the most likely one.
Re: Probability of 0.5
Thank you for reply.
And the others reason are
And the others reason are
Re: Probability of 0.5
The probability could be exactly 0.5 in the data or the distribution could be fixed.
Have you tried randomizing? That could break the 0.5 probability.
Have you tried randomizing? That could break the 0.5 probability.
Re: Probability of 0.5
Thanks you for reply!!!mark wrote:The probability could be exactly 0.5 in the data or the distribution could be fixed.
Have you tried randomizing? That could break the 0.5 probability.
I didn't tried randomizing, in my data all variables are observed ,due to i use complete data when learing the conditional probability table.
so, i think that could be distribution fixed.
Re: Probability of 0.5
Distributions are only fixed when you fix them yourself, which I suspect is not the case. Having complete data is not a sufficient condition to get rid of 0.5 probabilities. What you need is that for each family (child plus its parents) all parent configurations occur in the data. Especially when a node has many parents, this does not always happen.