Myopic Value of Information in Influence Diagrams

We present a method for calculation of my­ opic value of information in influence dia­ grams (Howard & Matheson, 1981) based on the strong junction tree framework (Jensen et al., 1994). An influence diagram specifies a certain or­ der of observations and decisions through its structure. This order is reflected in the corre­ sponding junction trees by the order in which the nodes are marginalized. This order of marginalization can be changed by table ex­ pansion and use of control structures, and this facilitates for calculating the expected value of information for different information scenarios within the same junction tree. In effect, a strong junction tree with expanded tables may be used for calculating the value of information between several scenarios with different observation-decision order. We compare our method to other methods for calculating the value of information in in­ fluence diagrams.