The SGP Package is open source software built for the R software environment. The classes, functions and data within the SGP package are used to calculate student growth percentiles and percentile growth projections/trajectories using large scale, longitudinal assessment data. Quantile regression is used to estimate the conditional density associated with each student’s achievement history. Percentile growth projections/trajectories are calculated using the derived coefficient matrices and show the percentile growth needed to reach future achievement targets.



To install the latest stable release of SGP from CRAN

> install.packages("SGP")

From Github

To install the development release of SGP from GitHub:

> devtools::install_github("CenterForAssessment/SGP")


The SGP Package is crafted with ❤️ by:

We love feedback and are happy to answer questions.


Betebenner, D. W., VanIwaarden, A., Domingue, B., and Shang, Y. (2017). SGP: Student Growth Percentiles & Percentile Growth Trajectories.

R Development Core Team (2017). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. 3-900051-07-0.