The availability of annual student achievement data and the dissatisfaction with status reporting of assessment results have led to widespread enthusiasm for statistical models suitable for longitudinal analysis. In response, the United States Department of Education recently solicited growth model proposals from states as a means of satisfying No Child Left Behind (NCLB) adequate yearly progress requirements. It is not surprising, given the intense focus on schools and their impact on student achievement, that most of the proposed growth models are formulated and implemented primarily as school accountability models. In this chapter, I suggest that the use of such models has led to a blind spot concerning other uses of longitudinal test data, especially for descriptive or diagnostic ends. The purpose of the chapter is twofold: (1) to situate growth analyses within a larger search for measures of school quality, and (2) to introduce student growth percentiles as a means of understanding student growth normatively. I demonstrate how student growth percentiles, analogous to pediatric growth charts, can help various stakeholders understand change in student assessment outcomes and its relationship to accountability systems designed to monitor educational quality.