Process evaluation compares presupposed objectives with actual inputs, activities, and outputs to determine whether and why the objectives have or have not been met. It is one of many tools (e.g., needs assessment, outcome evaluation, and impact evaluation) employed in evaluating programs. A program can be broadly described as a system of resources and activities allocated to the advancement of one or more goals; programs include interventions, services, and policies initiated and executed by public, nonprofit, or private providers at one or multiple locations. This entry describes (a) the history of process evaluation, including its materialization and proliferation as a facet of program evaluation, (b) the fit of process evaluation within the context of program evaluation, (c) the structure and flow of process evaluation from ...