# About SGP

### An R Package for the calculation & visualization of student growth percentiles and percentile growth trajectories/projections

The **SGP** Package (Betebenner, VanIwaarden, Domingue, Shang, 2014) is an open source package built for the open source **R** software environment (R Development Core Team, 2014).
The classes, functions and data within the **SGP** package are used to calculate student growth percentiles and percentile growth trajectories/projections using large scale, longitudinal assessment data. The methodology uses quantile regression to estimate the conditional density associated associated with each studentâ€™s achievement history. Percentile growth projections/trajectories are calculated using the coefficient matrices derived from the quantile regression analyses and specify the percentile growth required for students to reach future achievement targets.

### Team Members

The **SGP** Package is crafted with :heart: by:

We love feedback and are happy to answer questions.

### Install the latest stable release from CRAN

```
install.packages("SGP")
require(SGP)
```

### Install latest development release from Github :octocat:

```
install.packages("devtools")
require(devtools)
install_github("SGP", "CenterForAssessment")
require(SGP)
```

To install from Github you might need: Windows: Rtools (http://cran.r-project.org/bin/windows/Rtools/), OS X: xcode (from the app store),
Linux: apt-get install r-base-dev (or similar).

### To use the SGP Package

The SGP Package Wiki contains instructions on how to prepare data and run SGP analyses.

### Bibliography

Betebenner, D. W., VanIwaarden, A., Domingue, B., and Shang, Y. (2014). SGP: An R Package for the Calculation and Visualization of Student Growth Percentiles & Percentile Growth Trajectories.

R Development Core Team (2014). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.
3-900051-07-0.