GEORGIA BASELINE SGP ANALYSES
Methodology and results associated with Georgia Baseline SGP analyses
Damian W Betebenner
National Center for the Improvement of Educational Assessment
Atlanta, GA February 11th, 2015
RATIONALE FOR BASELINE ANALYSES
• Student growth percentiles are norm-referenced.
• For accountability purposes, Georgia desired a metric that
allowed for “all boats to rise” similar to criterion referenced
achievement.
• Following Massachusetts, Georgia began calculating baseline
referenced SGPs.
• The analyses were extended in 2013 to include measurement
error correction.
RATIONALE FOR BASELINE ANALYSES
Taxonomy of Measures from Carlson (2001)
REQUIREMENTS FOR BASELINE ANALYSES
• Comparisons over time (column 2) require a time invariant scale.
• Improvement in percent pro cient requires a stable pro ciency
threshold.
• Baseline growth requires a stable scale since the coef cient
matrices utilize scale scores to reference quantile cuts.
• The vast majority of content area by grade analyses in MA and
GA support the hypothesis that the scales are well equated.
• MA (one example) and GA (~5 examples) show
abnormally large deviations from year to year.
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SGP BASELINE ANALYSES
• Baseline analyses utilize multiple cohorts of students for each
analysis.
• For Biology the super cohort consist of 2007-2012 data including:
• 2007-2010 Grade 7 Science
• 2008-2011 Grade 8 Science
• 2009-2012 Biology
• A super-cohort is used to “average” any scale or population
abnormalities.
ANALYSES
• Scale score analyses were conducted for:
• Biology
• (mSGP 2010-2014: 48.7/48.7/50.0/49.7/45.0)
• American Literature
• (mSGP 2010-2014: 55.6/48.8/43.9/43.7/48.7)
• CRCT Mathematics (Grades 5, 7 & 8):
• (Grade 5 mSGP 2009-2014: 45.1/52.5/51.3/48.7/43.8/49.6)
• (Grade 7 mSGP 2009-2014: 49.6/50.5/49.2/50.7/45.4/40.6)
• (Grade 8 mSGP 2009-2014: 51.7/51.3/48.5/47.5/49.3/50.4)
About this copy
Georgia Baseline SGP Analyses — Georgia Department of Education, February 11, 2015.
This is an image-based copy of the original Keynote slides; builds and animations are flattened.