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What if I do not have any prior specification about the relationship between two varibales. Still BayesiaLab determines the causality. So what instruction does bayesiaLab follow?
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Library
BayesiaLab never determines causality automatically. It either uses the temporal indexes or the expert manual orientation of the arcs. At the end of the day, this is always the analyst that qualifies the BBN as a Causal BBN. However, a BBN is an oriented graph. This is the reason why we need to select an orientation, even when two orientations are equivalent for representing the joint probability distribution and have the same MDL score. Therefore, after structural learning, you do not have to directly interpret these oriented arcs as causal relations. Note that we do have a tool in Analysis – Visual – Show the Edges menu that transforms the BBN in an Essential Graph, where the arcs for which both orientations are equivalent are displayed as simple edges (undirected). The remaining arcs are the arcs belonging to V-Structures and the arcs that cannot be inverted without introducing spurious V-Structures or directed cycles. Example:causalStructure6.jpeg causalStructure7.jpeg causalStructure8.jpeg The arcs of the Essential Graph do not have to be directly interpreted as causal either. They indicates that changing their orientation will change the represented joint probability distribution.
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