Projection Models are Superior to Student Growth
Percentiles for K-12 Accountability Systems???
Damian W. Betebenner
National Center for the Improvement of Educational Assessment
Dover, NH
NCME Throwdown of the Day
San Francisco, CA
April 28th, 2013
Damian W. Betebenner Projection Models are Superior to SGP
Main Points
The SGP Model is intended to allow stakeholders to answer three
questions simultaneously:
What is? What is a student’s growth is answered in a
norm-referenced fashion using student growth
percentiles.
What should be? What should a student’s growth be to reach or
maintain desired levels of achievement is a
criterion-referenced question and is answered using
student growth projections.
What is reasonable? Because SGPs are percentiles and are
conditional probabilities, we implicitly understand
what is a modest growth goal versus what is an
ambitious growth goal.
One needs both norms and criteria to fully understand all
phenomena, including student growth.
Thus, to answer the debate question, one needs both student
growth percentiles (norms) and student growth projections (criteria)
to make sense.
Damian W. Betebenner Projection Models are Superior to SGP
Demonstration: 2012−2013 Mathematics
Norm & Criterion Referenced Growth & Achievement
Baseline Referenced Percentile Growth Trajectory
Scale Score
2012−2013 Achievement Percentile
Grade 3 Grade 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Grade 10
Advanced Reading
High
Achievement
CSAP Reading
● Typical
Scale Score
Proficient Growth
Low
● Level Percentiles
High 66th − 99th
Typical 35th − 65th
Part Proficient
● Low 1st − 34th
Unsatisfactory
Grade 3 Grade 4 Grade 5 Grade 6 Next Year
Scale Score 462 539 563 609
Achievement Level Unsatisfactory Part Proficient Part Proficient Proficient Achievement
Growth Percentile 66 66 90
Growth Level High High High Growth
About this copy
Projection Models are Superior to Student Growth Percentiles for K-12 Accountability Systems??? — NCME Annual Meeting, April 2013.
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