School districts across the United States increasingly use value-added models (VAMs) to evaluate teachers. In practice, VAMs typically rely on lagged test scores from the previous academic year, which necessarily conflate summer with school-year learning and potentially bias estimates of teacher effectiveness. We investigate the practical…

We apply "value-added" models to estimate the effects of teachers on an outcome they cannot plausibly affect: student height. When fitting the relatively simple models that are widely used in educational practice to New York City data, we find the standard deviation of teacher effects on height is nearly as large as that for math and…

Papay (2011) noticed that teacher value-added measures (VAMs) from a statistical model using the most common pre/post testing timeframe--current-year spring relative to previous spring (SS)--are essentially unrelated to those same teachers' VAMs when instead using next-fall relative to current-fall (FF). This is concerning since this choice--made…

Despite growing interest in the importance of nonacademic skills for student success, very few studies have examined the extent to which schools and teachers are associated with gains in these outcomes. This descriptive study adds to the nascent literature by examining the amount of school- and teacher-associated variation in kindergarten…

Accurately measuring and modeling academic achievement growth is critical to support educational policy and practice. Using a nationally representative longitudinal data set, this study compared various models of mathematics achievement growth on the basis of both practical utility and optimal statistical fit and explored relationships within and…

This study examines the effects of including the summer period on value-added assessments (VAA) of teacher and school performance at the early grades. The results indicate that 40-62% of the variance in VAA estimates originates from the summer period, depending on the outcome (i.e., reading or math achievement gains). Furthermore, when summer is…

The growing availability of data linking students to classroom teachers has made it possible to estimate the contribution teachers make to student achievement. While there is a growing consensus that teacher quality is important and current evaluation systems are inadequate, many have expressed concerns over the use of value-added measures (VAMs)…