Compare methods

	Student Growth Percentiles	Value-Added Teacher Evaluation
Field	Education	Education
Family	Regression model	Regression model
Year of origin	2009	2004
Originator	Damian W. Betebenner	William Sanders (TVAAS); methodological critique by McCaffrey, Lockwood, Koretz et al.
Type	Normative growth description via conditional quantile regression	Statistical estimation of individual teachers' contributions to student achievement growth
Seminal source	Betebenner, D. W. (2009). Norm- and criterion-referenced student growth. Educational Measurement: Issues and Practice, 28(4), 42–51.	McCaffrey, D. F., Lockwood, J. R., Koretz, D., Louis, T. A., & Hamilton, L. (2004). Models for value-added modeling of teacher effects. Journal of Educational and Behavioral Statistics, 29(1), 67–101.
Aliases	SGP, Conditional Status Percentiles, Betebenner Growth Percentiles, Quantile-Regression Growth Model	Teacher Value-Added Models, VAM for Teachers, Teacher Effect Estimation, Value-Added Teacher Accountability
Related	4	4
Summary	Student growth percentiles (SGPs) describe how much a student grew academically relative to peers with similar score histories. Introduced by Damian Betebenner in 2009, the method fits a series of conditional quantile regressions of a current test score on prior scores, then reports each student's growth as the percentile rank they occupy within the distribution of students who had the same starting point. A student at the 70th growth percentile grew faster than 70 percent of academic peers, regardless of their absolute achievement level.	Value-added teacher evaluation uses longitudinal student test scores to estimate how much individual teachers contribute to their students' achievement growth, net of what students brought into the classroom. Statistically it applies value-added and mixed-model machinery — controlling for prior achievement and student characteristics, then treating each teacher's residual contribution as an effect to be estimated. Pioneered in Tennessee's TVAAS and scrutinized in a large methodological and policy literature, it became central, and controversial, in teacher accountability.