- A substantial portion of the variance in YoY (Year over Year) VAA estimates originates from summer and that summer variance alters the quintile rankings of a high percentage of teachers and schools.
- The summer effect invariably underestimated the performance of teachers and schools in the lowest quintile of summer change and overestimated the performance of teachers and schools in the highest quintile of summer change.
- Including an extensive number of demographic and contextual variables does not substantively reduce the summer effects on VAA estimates. These results suggest that twice-annual assessment may be necessary to remove the summer effects from VAA estimates.
- Including summer in VAA estimates results in systematic biases against schools serving higher concentrations of students who qualify for FRL. Students from low SES families tend to have greater declines in reading achievement over summer, but learn at similar rates as other students during the school year.