Data Sgp is a data set and function package for creating student growth percentile reports. The package is designed to make it easy for teachers to use student data to identify students who need additional support and help them achieve academic success. Student growth percentiles show relative progress by comparing a student’s MCAS score to the scores of students with similar prior achievement levels. This allows students to see how much they have improved and provides an opportunity to recognize their achievements, even when their actual MCAS score may be below proficiency.
SGPs are an important tool for assessing student progress and educator effectiveness. In general, ranking students against their peers is perceived as more fair and relevant than examining unadjusted achievement levels alone (Betebenner, 2009). Students who are below or above average in terms of MCAS score may still improve or decline from year to year depending on the circumstances.
In addition, student growth percentiles can provide a more complete picture of student performance, as they are often adjusted to account for student background factors such as socioeconomic status and family education level.
Despite these benefits, it is important to remember that SGPs can have limitations when used as indicators of teacher quality. The most obvious limitation is that SGPs are based on standardized test scores, which are error-prone measures of latent achievement traits. These errors make SGPs noisy measures of the “true” latent achievement trait for each student.
Another limitation is that SGPs are correlated with the student covariates that were observed in each teacher’s classroom, a source of variance that is difficult to remove. This is a concern when SGPs are aggregated to the school or district level and interpreted as an indicator of educator effectiveness, because it suggests that differences in student growth across teachers may be due to unobserved teacher effects rather than student background factors.
The higher correlations between SGPs and student covariates in grades 7 and 8 are likely due to the greater within-grade, cross-year correlations of the latent achievement traits in these grades compared to earlier grades. However, the relationships between true SGPs and student covariates are also likely to reflect some degree of confounding due to unequal distribution of these variables across teachers’ classrooms. The final limitation is that the relationships between SGPs and student covariates could be the result of other, unmeasured factors influencing both student growth and covariate patterns. This would require further research. However, the interpretation of SGPs as a measure of teacher quality is not impossible, and alternative models that regress student test scores on teacher fixed effects and prior test scores should be explored. These models offer the potential to remove some of the noise associated with SGPs and their interpretation as indicators of teacher quality. This would be especially important if SGPs are used to evaluate educator effectiveness in value-added analyses.