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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 and Contrast-Coded Direct Covariates Used in the Population-Structure Model, Grade 8 U.S. History National Assessment, by Type of Contrast: 2022
NAEP Technical DocumentationProportion of Variance of the Group-Defining Contrasts Accounted for by the Principal Components and Contrast-Coded Direct Covariates Used in the Population-Structure Model, Grade 8 U.S. History National Assessment, by Type of Contrast: 2022
| Type of contrast | Number of contrasts | Mean | Total | Reportable | Number of contrasts by proportion of variance explained | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | .00 - .70 | .70 - .80 | .80 - .90 | .90 - .95 | .95 - 1.00 | |||
| (Total Variance – Residual Variance) / Total Variance, where Total Variance includes variance accounted and unaccounted for by the variables in the population-structure model. | |||||||||||
| The major reporting variables include the contrasts from the direct covariates. SD/EL = Students with disabilities/English learners. | |||||||||||
| U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2022 U.S. History Assessment. | |||||||||||
| All contrasts | 1599 | .88 | .09 | 1.00 | .14 | 1.00 | 192 | 94 | 224 | 257 | 832 |
| Student questionnaire | 451 | .91 | .14 | 1.00 | .14 | 1.00 | 34 | 13 | 44 | 72 | 288 |
| Major reporting variables | 99 | .83 | .09 | 1.00 | .26 | 1.00 | 20 | 4 | 13 | 13 | 49 |
| Interactions between reporting variables | 232 | .73 | .11 | .99 | .33 | .99 | 87 | 27 | 31 | 33 | 54 |
| Teacher questionnaire | 470 | .92 | .39 | .99 | .53 | .99 | 19 | 29 | 77 | 84 | 261 |
| School questionnaire | 314 | .93 | .59 | .99 | .65 | .99 | 5 | 18 | 57 | 54 | 180 |
| SD/EL questionnaire | 33 | .46 | .14 | .93 | .22 | .93 | 27 | 3 | 2 | 1 | 0 |
Last updated 24 July 2024 (SK)