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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: 2010
| Type of contrast | Number of contrasts | Mean | Minimum | Maximum | Number of contrasts by proportion1 of variance explained | ||||
|---|---|---|---|---|---|---|---|---|---|
| 0.00 - 0.70 | 0.70 - 0.80 | 0.80 - 0.90 | 0.90 - 0.95 | 0.95 - 1.00 | |||||
| 1 (Total Variance – Residual Variance)/Total Variance, where Total Variance consists of both sampling and measurement error variance. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2010 U.S. History Assessment. |
|||||||||
| All contrasts | 1401 | 0.90 | 0.63 | 1.00 | 12 | 58 | 584 | 466 | 281 |
| Student questionnaire | 195 | 0.89 | 0.63 | 0.99 | 5 | 19 | 58 | 75 | 38 |
| Major reporting variables | 64 | 0.92 | 0.78 | 1.00 | 0 | 2 | 26 | 14 | 22 |
| Interactions between reporting variables | 465 | 0.91 | 0.65 | 0.99 | 7 | 32 | 121 | 158 | 147 |
| Teacher questionnaire | 385 | 0.89 | 0.80 | 0.98 | 0 | 0 | 234 | 117 | 34 |
| School questionnaire | 257 | 0.91 | 0.84 | 0.99 | 0 | 0 | 133 | 90 | 34 |
| SD/ELL questionnaire | 35 | 0.88 | 0.76 | 0.98 | 0 | 5 | 12 | 12 | 6 |
Last updated 05 January 2016 (GF)
