Including costs in evaluations changes how program providers, participants, policy-makers, and funders perceive programs. That can be good. When we report how well programs implement plans, we evaluate fidelity. When we report changes in outcomes targeted by programs such as behaviors, thoughts, feelings of individuals or communities, we evaluate effectiveness. If we report the value of resources consumed by programs, we evaluate costs. Assessing the value of resources generated by programs evaluates benefits. Measuring costs of programs relative to benefits evaluates cost-benefit. Considering costs of programs relative to effectiveness evaluates cost-effectiveness. Comparing cost-benefit or cost-effectiveness of competing programs can be exciting, difficult, and helpful in getting the attention of the powerful. Including costs in evaluations can help evaluations get used.