(a) Evaluation is a more in-depth, rigorous effort to measure the impact of programs. While performance measurement and evaluation both include systematic data collection and measurement of progress, evaluation uses scientifically-based research methods to assess the effectiveness of programs by comparing the observed program outcomes with what would have happened in the absence of the program. Unlike performance measures, evaluations estimate the impacts of programs by comparing the outcomes for individuals receiving a service or participating in a program to the outcomes for similar individuals not receiving a service or not participating in a program. For example, an evaluation of a literacy program may compare the reading ability of students in a program over time to a similar group of students not participating in a program.

(b) Performance measurement is the process of systematically and regularly collecting and monitoring data related to the direction of observed changes in communities, participants (members), or end beneficiaries receiving your program's services. It is intended to provide an indication of your program's operations and performance. In contrast to evaluation, it is not intended to establish a causal relationship between your program and a desired (or undesired) program outcome. For example, a performance measure for a literacy program may include the percentage of students receiving services from your program who increase their reading ability from “below grade level” to “at or above grade level”. This measure indicates something good is happening to your program's service beneficiaries, but it does not indicate that the change can be wholly attributed to your program's services.