Programs and policies invariably contain new knowledge. Theories about knowledge utilization, diffusion, implementation, transfer, and knowledge translation theories illuminate some mechanisms of change processes. But more often than not, when it comes to understanding patterns about change processes, "the foreground" is privileged more than "the background". The foreground is the knowledge or technology tied up with the product or program that prompted the evaluation. The background is the ongoing dynamics of the context into which the knowledge is inserted. Complex adaptive system thinking encourages greater attention to this context and the interactions and consequences that result from the intervention, making these the forefront of attention. For the evaluator, there are implications of this shift in thinking. Process evaluations should be designed to capture the fluidity of the change process. Impact and outcome evaluations will require long time frames. Complex adaptive system thinking also encourages multilevel measures, a focus on structures, and capacity to assess the possibility of whole system transformation (whole school, whole organization) as a result of the newly introduced program or policy. For the people involved in the innovation, there is a corresponding shift from a focus on their knowledge (and competence) to assessment of their learning (and system-level capability). New ways to interpret fidelity in these situations should therefore be developed. (Contains 2 tables.)