VAMs v. Student Growth Percentiles (SGPs)

Yesterday (11/4/2013) a reader posted a question, the first part of which I am partially addressing here: “What is the difference [between] VAM[s] and Student Growth Percentiles (SGP[s]) and do SGPs have any usefulness[?]” One of my colleagues, soon to be a “Guest Blogger” on TheTeam, but already an SGP expert, is helping me work on a more nuanced response, but for the time-being please check out the Glossary section of this blog:

VAMs v. Student Growth Models: The main similarities between VAMs and student growth models are that they all use students’ large-scale standardized test score data from current and prior years to calculate students’ growth in achievement over time. In addition, they all use students’ prior test score data to “control for” the risk factors that impact student learning and achievement both at singular points in time as well as over time. The main differences between VAMs and student growth models are how precisely estimates are made, as related to whether, how, and how many control variables are included in the statistical models to control for these risk and other extraneous variable (e.g.,  other teachers’ simultaneous and prior teacher’s residual effects). The best and most popular example of a student growth model is the Student Growth Percentiles (SGP) model. It is not a VAM by traditional standards and definitions, mainly because the SGP model does not use as many sophisticated controls as does its VAM counterparts.

See more forthcoming…

One thought on “VAMs v. Student Growth Percentiles (SGPs)

  1. Dr. Amrein-Beardsley, New Jersey now employs the SGP model. Anyone can go to State website, AchieveNJ, and get two written explanations how the DOE is using this measure.
    {I worry that a DetailedGeneral Student Growth Percentile is as much an oxymoron as the concept behind it.}

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