What counts as good teaching? How a student growth percentile model has defined teacher quality at one urban middle school

Employing a discursive analytical approach, the author of this chapter explores the practical and theoretical implications of the Student Growth Percentile (SGP) model as experienced by teachers and their evaluators at one urban middle school. The school had relied on the SGP model to evaluate teachers for four years by the time of the study. Over the course of a year, the author collected in-depth interviews with both teachers and their evaluators (i.e., peer evaluators and school-based administrators) regarding their experiences with the SGP model. She found that, despite expressed concerns with the reliability and validity of SGP estimates, the teachers and evaluators had developed an acceptance of the system and had begun to define teachers and teacher effectiveness in terms of the model results.