NAEP tdw - Proportion of Variance of the Group-Defining Contrasts Accounted for by the Principal Components Used in the Population-Structure Model, Grade 8 Reading Combined National and State Assessment: 2013

NAEP Analysis and Scaling → Estimation of Population and Student Group Distributions → Examining the Population-Structure Models Used in NAEP → Proportion 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 8 Reading 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 8 reading combined national and state assessment: 2013
Type of contrast	Number of contrasts	Mean	Minimum	Maximum	Number of contrasts by proportion¹ of variance explained
Type of contrast	Number of contrasts	Mean	Minimum	Maximum	.00 - .70	.70 - .80	.80 - .90	.90 - .95	.95 - 1.00
¹(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.
All contrasts	1512	.90	.64	1.00	11	79	553	556	313
Student questionnaire	181	.89	.64	.99	3	25	41	61	51
Major reporting variables	120	.93	.71	1.00	0	3	28	40	49
Interactions between reporting variables	377	.90	.64	.98	8	21	102	193	53
Teacher questionnaire	275	.91	.70	.99	0	11	81	90	93
School questionnaire	525	.89	.74	.98	0	17	293	163	52
SD/ELL questionnaire	34	.92	.77	1.00	0	2	8	9	15

Last updated 21 May 2017 (DC)