SGP-package {SGP}R Documentation

Functions to calculate student growth percentiles and percentile growth projections/trajectories following methodology found in Betebenner (2008)

Description

SGP contains two functions, studentGrowthPercentiles and studentGrowthProjections, used to calculate student growth percentiles and percentile growth projections/trajectories for students using large scale, longitudinal assessment data. These norm referenced growth values are currently used in state testing and accountability systems. The functions employ quantile regression (using the quantreg package) to estimate the conditional density associated with each student's achievement history. Percentile growth projections/trajectories are calculated using the coefficient matrices derived from the student growth percentile analyses.

Details

Package: SGP
Type: Package
Version: 0.0-3
Date: 2009-2-15
License: Creative Commons Attribution + ShareAlike (by-sa)
LazyLoad: yes

Calculation of student growth percentiles is typically performed by grade and subject. Data for growth percentile calculation must be specifically formatted. See sgpData for an example data set. Batch R syntax for performing analyses across all grades is provided in the examples of the studentGrowthPercentiles and studentGrowthProjections functions. Calculation of percentile growth projections/trajectories follows calculation of student growth percentiles and requires coefficient matrices derived during student growth percentile estimation.

Author(s)

Damian W. Betebenner DBetebenner@nciea.org

References

Koenker, R. (2005). Quantile regression. Cambridge: Cambridge University Press.

Betebenner, D. W. (2008). Toward a normative understanding of student growth. In K. E. Ryan & L. A. Shepard (Eds.), The Future of Test Based Accountability (pp. 155-170). New York: Routledge.


[Package SGP version 0.0-3 Index]