Table of Contents | Search Technical Documentation | References
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 Civics 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 Civics 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 Civics Assessment. | |||||||||||
| All contrasts | 1619 | .88 | .12 | 1.00 | .15 | 1.00 | 192 | 98 | 221 | 273 | 835 |
| Student questionnaire | 260 | .87 | .15 | 1.00 | .15 | 1.00 | 28 | 19 | 30 | 50 | 133 |
| Major reporting variables | 304 | .92 | .12 | 1.00 | .24 | 1.00 | 21 | 6 | 27 | 44 | 206 |
| Interactions between reporting variables | 238 | .72 | .13 | .99 | .27 | .99 | 93 | 25 | 29 | 38 | 53 |
| Teacher questionnaire | 469 | .92 | .35 | .99 | .56 | .99 | 19 | 29 | 76 | 87 | 258 |
| School questionnaire | 317 | .93 | .59 | .99 | .62 | .99 | 6 | 16 | 57 | 53 | 185 |
| SD/EL questionnaire | 31 | .47 | .14 | .93 | .20 | .93 | 25 | 3 | 2 | 1 | 0 |
Last updated 24 July 2024 (SK)