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NAEP Analysis and ScalingEstimation of Population and Student Group DistributionsExamining the Population-Structure Models Used in NAEPProportion of Variance Accounted For by Principal Components Used in NAEP Population-Structure Models → Proportion of Variance of the Group-Defining Contrasts Accounted for by the Principal Components Used in the Population-Structure Model, Grade 12 Meaning Vocabulary Combined National and State Assessment: 2013
NAEP Technical DocumentationProportion of variance of the group-defining contrasts accounted for by the principal components used in the population-structure model, grade 12 meaning vocabulary combined national and state assessment: 2013
Type of contrastNumber of contrastsMeanMinimumMaximumNumber of contrasts by proportion1 of variance explained
.00 - .70.70 - .80.80 - .90.90 - .95.95 - 1.00
† Not applicable.
11 (Total Variance – Residual Variance)/Total Variance, where Total Variance consists of sampling, measurement, and other sources of error.
NOTE: SD/ELL = Students with disabilities/English language learners.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2013 Reading Assessment.
Total45.91.6013361716
Student questionnaire5.98.95100014
Major reporting variables17.93.87100386
Interactions between reporting variables23.88.60133386
Teacher questionnaire
School questionnaire
NIES questionnaire
SD/ELL questionnaire

Last updated 21 May 2017 (DC)