Some states that evaluate teachers based partly on student learning use the student growth percentile model, which computes a score that is assumed to reflect a teacher’s current and future effectiveness for helping to increase student academic achievement.

However, a recent REL West study found that half or more of the variance in teacher scores from this model is due to random or otherwise unstable sources rather than to reliable information that could predict future performance.

Visit the Analysis of the Stability of Teacher-Level Growth Scores From the Student Growth Percentile Model resource page to learn more and download a free copy.