BNs vs MNs
Post on 17-Jan-2016
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Daphne Koller
Wrapup
BNs vs MNs
ProbabilisticGraphicalModels
Representation
Consider representing a given P using a graphical model. Which of the following is correct?
P can always be represented as a BN but maybe not an MN.
P always can be represented as an MN but maybe not a BN.
P can always be represented both as a BN and as an MN.
It’s possible that P can be represented as neither a BN nor an MN.
Consider representing a given P using a graphical model, where our goal is to capture I(P) exactly. Which of the following is correct?
I(P) can always be represented as a BN but maybe not an MN.
I(P) always can be represented as an MN but maybe not a BN.
I(P) can always be represented both as a BN and as an MN.
It’s possible that I(P) can be represented using neither a BN nor an MN.
Daphne Koller
Bayes Net as Gibbs DistributionIntelligenceDifficulty
Grade
Letter
SAT
IntelligenceDifficulty
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Letter
SAT
IntelligenceDifficulty
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SAT
IntelligenceDifficulty
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Letter
SAT
IntelligenceDifficulty
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SAT
Which of the following undirected graphs is the minimal I-map for the distribution P encoded by the BN on the right?
IntelligenceDifficulty
Grade
Letter
SAT
Daphne Koller
What Do We Lose?
IntelligenceDifficulty
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Letter
SAT
IntelligenceDifficulty
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SAT
BD
C
A
BD
C
AConsider a distribution P represented perfectly by the MN H. Which of the following are true? Mark all that apply.
G is a minimal I-map for P
H G
G is an I-map for P but is not minimal G is not an I-map for P because G is not an I-map for P because
Daphne Koller
What Do We Lose?
BD
C
A
Daphne Koller
Which Should I Use?
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