| Belief Networks |
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| • | Assume
variables are conditionally independent by |
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| default. |
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| • | Only
represent direct causal links (conditional |
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| dependence)
between random variables. |
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| • | Belief
network or Bayesian network: |
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| 1. | set
of random variables (nodes) |
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| 2. | set
of directed links (edges) indicating direct influence of one |
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| variable
on another. |
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| 3. | a
table for each variable, supplying conditional probabilities of |
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| the
variable for each assignment of its parents |
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| 4. | no
directed cycles (network is a DAG) |
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