Although evaluation serves many purposes in education, there is virtually unanimous agreement that evaluation is a critical component of all school improvement processes. Hamilton et al. (2003) asserted that "assessment and evaluation should be built into reform programs from the outset" (p. 26). Kimball, Lander, and Thorn (2010) extended this, calling for evaluation before, during, and after school improvement projects. Consequently, the purpose of this article is to explore when, how, and why evaluation should be utilized in formal school improvement processes.