There is an unstated assumption in much evaluation that the logic models and methodologies we put in place will remain relevant thought the evaluation's life cycle. We know better. We know that programs and their environments are often in a state of flux. But while we know this, we have done little to incorporate that knowledge into our evaluation planning. Of course this statement is an exaggeration, as evidenced by recognition in many evaluations that program environments must be scanned, that close observation of program activity is important, and that goal free evaluation has its place. Still, we have a meager set of tools, and minimal theoretical guidance, to help us evaluate unintended consequences of program action. Disciplines such as planning, social change, and system dynamics have devoted a great deal of energy to understanding unintended consequences, and as a result, evaluators have a pool of knowledge to draw from. We could use this knowledge to develop evaluation theories and methods, but so far we have put little effort into doing so. One purpose of this panel is to provide information on some of those theories and methods. A second purpose is to cohere a group of people who are willing to continue theory and method development on the subject of how evaluation should deal with unintended consequences of program action.