NAEP Technical Documentation

Original estimates are based on previous assessment data and previous assessment scaling results, transformed to the reporting metric using the transformation constants identified during the analysis of the previous assessment data. Provisional estimates are based on previous assessment data and current assessment scaling results. Prior to transformation, provisional estimates are on the theta metric specified by the scaling program. The original and provisional estimates for the linking sample are used to find the transformation constants necessary to place the current assessment scale scores on the scale used to report previous assessment scale scores. The transformed provisional estimates are based on previous assessment data and current assessment scaling results, transformed to the reporting metric using the transformation constants calculated from the original and provisional estimates for the linking sample. If the transformation constants are correct, the original and transformed provisional means should be the same.

Comparison of means and percentiles of 2010 scores and 2010-transformed provisional scores, grade 8 civics national assessment: 2014

Statistic	Original 2010 estimate	2010-transformed provisional estimate	Difference between the transformed provisional estimate and the original estimate
# Rounds to zero. NOTE: Single overall scale. In 2014, grades 4 and 12 were not assessed. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2014 Civics Assessment.
Mean	151.31	151.31	#
10th percentile	105.85	105.85	#
25th percentile	130.51	130.44	-0.07
50th percentile	155.03	154.99	-0.04
75th percentile	175.41	175.45	0.04
90th percentile	191.32	191.37	0.05

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