Do smaller schools really reduce the “power rating” of poverty?

Theodore Coladarci


The percentage of variance in student achievement that is explained by student SES—“poverty’s power rating,” as some call it—tends to be less among smaller schools than among larger schools. Smaller schools, we are told, are able to somehow disrupt the association between SES and student achievement. Using eighth-grade data for 215 public schools in Maine, I explored the hypothesis that this finding is in part a statistical artifact of the lower reliability of school-aggregated student achievement in smaller schools. This hypothesis was supported for mathematics achievement but seemingly not for reading achievement. Implications are discussed.


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