ABSTRACT While states are no longer required to set up teacher evaluation systems based in significant part on student test scores, quite a few continue to use value-added (VAMs) or student growth percentile (SGP) models for that purpose. In this study, we analyzed three years of teacher data to illustrate the performance of teachers’ median growth percentiles (MGPs)). We found MGP’s consistency over time to be comparable with the existing estimates from the value-added models (VAMs). Additionally, we found that MGPs do not substantively agree with another measure of teacher quality – teachers’ observational scores. These findings suggest that caution should be exercised when teacher’s MGPs, as well as VAMs, are used in teacher evaluation system to make high-stakes decisions such as merit pay, tenure, or teacher contract termination. Our findings about the correlation of MGPs with observational scores support the idea of the multidimensional nature of teacher effectiveness construct.

中文翻译：

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中位数增长百分位数（MGP）：跨期稳定性及其与观察评分的相关性评估

摘要虽然不再需要州政府在很大程度上基于学生考试成绩来建立教师评估系统，但仍有许多国家继续为此目的使用增值（VAM）或学生成长百分比（SGP）模型。在这项研究中，我们分析了三年的教师数据，以说明教师的中位数增长百分比（MGP）的表现。我们发现，MGP随时间推移的一致性可以与增值模型（VAM）的现有估算相媲美。此外，我们发现，MGP基本上与另一项衡量教师质量的标准（教师的观察分数）不一致。这些发现表明，在教师评估系统中使用教师的MGP和VAM做出高风险的决策（如绩效工资，任期或终止教师合同）时，应谨慎行事。