20. The method of claim 16 wherein the decision graph has nodes corresponding to a plurality of the nodes of the belief network, the method further including the step of when the decision graph adjustment adds a node to the decision graph whose corresponding node in the belief network is not a parent to the at least one of the nodes in the belief network, updating the belief network to indicate that a value of the corresponding node causally influences the at least one of the nodes in the belief network.
20. The method of claim 16 wherein the decision graph has nodes corresponding to a plurality of the nodes of the belief network, the method further including the step of when the decision graph adjustment adds a node to the decision graph whose corresponding node in the belief network is not a parent to the at least one of the nodes in the belief network, updating the belief network to indicate that a value of the corresponding node causally influences the at least one of the nodes in the belief network. 21. The method of claim 20 wherein the update to the belief network introduces a cycle.