Proportion of Variance of the Group-Defining Contrasts Accounted for by the Principal Components Used in the Population-Structure Model, Grade 8 U.S. History National Assessment: 2014

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 U.S. History National Assessment: 2014

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Proportion of Variance of the Group-Defining Contrasts Accounted for by the Principal Components Used in the Population-Structure Model, Grade 8 U.S. History National Assessment: 2014
Proportion of variance of the group-defining contrasts accounted for by the principal components used in the population-structure model, grade 8 U.S. history national assessment: 2014
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/EL = Students with disabilities/English learners. 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 U.S. History Assessment.
Total	1221	.90	.62	.99	14	44	489	486	188
Student questionnaire	203	.89	.68	.98	6	17	62	82	36
Major reporting variables	75	.91	.77	.99	0	1	32	23	19
Interactions between reporting variables	247	.89	.62	.98	8	19	82	110	28
Teacher questionnaire	378	.90	.82	.99	0	0	208	110	60
School questionnaire	282	.92	.84	.99	0	0	91	149	42
SD/EL questionnaire	34	.87	.78	.97	0	7	14	10	3
Student questionnaire indices	2	.93	.93	.93	0	0	0	2	0

Last updated 30 August 2021 (ML)