It is important to evaluate Quality Rating and Improvement Systems (QRISs) so that policy makers and stakeholders can learn how well they are working and how they might be improved. Well-designed QRIS evaluations go beyond a "pass/fail" judgment to identify implementation successes and problems and assess what needs to be done to improve the system. A recent evaluation of a small QRIS field test in two communities in Washington State exemplifies what good evaluations can do. The evaluation provided useful findings for both policy makers and program developers by examining both "how" the QRIS was working (an implementation study), and whether the improvement approach was affecting child care quality. The findings informed a larger field test in five locations around the state. The purpose of this document is to encourage high-quality quality rating and improvement systems (QRIS) evaluations by providing timely information on evaluation options to those who may be in positions to authorize, finance, design, and refine QRISs and other quality improvement efforts, including state child care administrators, legislators, and other potential funders such as foundation personnel, as well as child care and early education provider organizations. This Brief presents basic evaluation concepts, useful tools for determining the appropriate design and timing of an evaluation, and evaluation references and resources for those who wish to learn more. Readers should come away with enough background to understand the basic issues in designing evaluations of quality improvement efforts and a stronger sense of their importance.