Influence diagrams for team decision analysis

We consider the representation and evaluation of team decision making under uncertainty using influence diagrams. We assume that all team members agree on common beliefs and preferences, but complete sharing of information is generally impossible. As a result, the team can be represented as a single rational individual with imperfect recall, and the optimal solution with perfect recall might not be achievable, except in special cases we can recognize. An alternative solution concept is a stable solution that integrates the notion of optimality with that of equilibrium from game theory. We extend this concept from individual decisions to sets of decisions, and introduce the Strategy Improvement and its variation, Uniform Strategy Improvement, as the corresponding solution methods. We also provide a variety of simplifying transformations to the influence diagram by exploiting its graphical structure. The result is a requisite influence diagram, one that requires minimum assessment and creates additional opportunities for optimality.