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 geography national assessment, by scale: 2014

Scale	Statistic	Original 2010 estimate	2010-transformed provisional estimate	Difference between the transformed provisional estimate and the original estimate
# Rounds to zero. NOTE:  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 Geography Assessment.
Composite scale	Mean	261.21	261.21	#
	10th percentile	220.01	219.93	-0.08
	25th percentile	241.01	241.21	0.20
	50th percentile	263.10	263.26	0.16
	75th percentile	283.68	283.53	-0.15
	90th percentile	299.61	299.47	-0.14
Space and place	Mean	261.06	261.06	#
	10th percentile	218.42	218.10	-0.32
	25th percentile	239.73	240.00	0.27
	50th percentile	262.89	262.93	0.04
	75th percentile	284.43	284.22	-0.21
	90th percentile	301.49	301.54	0.05
Environment and society	Mean	263.73	263.73	#
	10th percentile	219.61	219.82	0.21
	25th percentile	242.44	242.21	-0.23
	50th percentile	265.97	265.86	-0.11
	75th percentile	287.56	287.74	0.18
	90th percentile	304.67	304.74	0.07
Spatial dynamics and connections	Mean	258.88	258.88	#
	10th percentile	219.29	219.42	0.13
	25th percentile	239.76	239.92	0.16
	50th percentile	261.00	261.24	0.24
	75th percentile	280.26	280.08	-0.18
	90th percentile	295.25	295.18	-0.07

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