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Suppose I have two variables in my dataset. How BayesiaLab determines the causality. The MDL score will be same for both directions of the link, right? Thus, how exactly it determines the arrow?
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Library
Indeed, the MDL score will be the same for causalStructure1.png  and causalStructure2.png . Therefore, BayesiaLab will be unable to determine any causal direction by just using your dataset. In order to determine causality, you will have to use your expert knowledge (to set the causal direction manually) or use some temporal information (e.g. B occurs before A). If you have this temporal information, you will just have to define temporal indexes in BayesiaLab (by double clicking on the node to open the Node Editor).causalStructure3.jpeg causalStructure4.jpeg These indexes are taken into account while learning the structure to prevent links from the “future” to the “past”.causalStructure5.png 
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