This model is applied to performance measurement for programs that serve children, their families, and the communities where they live; therefore, it should be of interest to juvenile justice agencies and youth-serving organizations. The proposed four-quadrant approach to performance measurement is based on two sets of interlocking questions that all performance measures address; i.e., how much was done ("input") and how well was it done ("output"). Two quadrants compose each of these two sets. These quadrants measure "quantity" and "quality." The quantity for input is the amount of services delivered; the quality for input is how well the services were delivered. For output, the quantity quadrant measures how much was produced, and the quality quadrant measures the quality of the products. The findings produced for each of these four quadrants are ranked according to their importance in determining a program's performance. The top priority is given to the quadrant that measures the quality of the products produced. The second ranking is given to how well services were delivered. The third ranking is given to how much was produced, and the fourth ranking is given to how much service was delivered. The "Guide" provides examples of program performance measures obtained from using the four-quadrant approach. Sources of additional information are provided.