Unifying expert systems and the decision sciences

There are many tools and much literature that combine the expert systems and mathematical modeling paradigms. This survey focuses on a subset consisting of: decision making and unification, and not mere co-existance, of the two approaches. The unification effort is new and presents many research challenges at the theoretical, methodological, and tool levels. At the theoretical level, accepted prescriptions now exist that stipulate in which situations it is valid to use various forms of mathematical and qualitative reasoning. This is leading to a unified theory of the decision sciences for problems spanning choice, forecasting, risk assessment, design, operations, and many others. At the tool level three forms of synthesis of expert systems and mathematical models are particularly noteworthy: knowledge-based decision aids, intelligent decision modeling systems, and decision analytic expert systems. This survey gives definitions, surveys, and examples of each of these ways of unifying expert systems and modeling. Following this are lessons learned and further research needs. A great deal of synthesis work remains to be done, and a goal of this survey is to highlight some of the issues and invite discussion.