  In this paper we extend the influence diagram (ID) representation for
decisions under uncertainty. In the standard ID, arrows into a decision node
are only informational; they do not represent constraints on what the decision
maker can do. We can represent such constraints only indirectly, using arrows
to the children of the decision and sometimes adding more variables to the
influence diagram, thus making the ID more complicated. Users of influence
diagrams often want to represent constraints by arrows into decision nodes. We
represent constraints on decisions by allowing relevance arrows into decision
nodes. We call the resulting representation information/relevance influence
diagrams (IRIDs). Information/relevance influence diagrams allow for direct
representation and specification of constrained decisions. We use a combination
of stochastic dynamic programming and Gibbs sampling to solve IRIDs. This
method is especially useful when exact methods for solving IDs fail.
