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NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Block-Level Descriptive Statistics as Defined After Scaling, Grade 8 U.S. History National Assessment, by Block and School Type: 2022
NAEP Technical DocumentationBlock-Level Descriptive Statistics as Defined After Scaling, Grade 8 U.S. History National Assessment, by Block and School Type: 2022
| Statistic | Block H1 | Block H2 | Block H3 | Block H4 | Block H5 | Block H6 | Block H7 | Block H8 | Block H9 |
|---|---|---|---|---|---|---|---|---|---|
| The "Weighted average item score" of polytomous items is standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items. | |||||||||
| The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item / 100). | |||||||||
| The nonpublic school sample includes only private schools, including Catholic schools. BIE and DoDEA schools are not included in either the public or nonpublic category. Item statistics in this table are described on the page Blocks of Items. Weights are applied to reflect sampling design. | |||||||||
| 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. | |||||||||
| Number of scaled items | 23 | 20 | 22 | 23 | 20 | 22 | 21 | 20 | 21 |
| Public school | |||||||||
| Unweighted sample size | 1,700 | 1,700 | 1,600 | 1,600 | 1,700 | 1,600 | 1,700 | 1,600 | 1,700 |
| Weighted average item score | .49 | .43 | .45 | .42 | .45 | .44 | .46 | .41 | .46 |
| Weighted average R biserial/polyserial | .52 | .56 | .53 | .50 | .53 | .54 | .48 | .53 | .55 |
| Weighted alpha reliability | .79 | .81 | .81 | .78 | .80 | .80 | .74 | .76 | .80 |
| Weighted proportion of students attempting last item | .90 | .92 | .90 | .80 | .87 | .89 | .88 | .88 | .89 |
| Nonpublic school | |||||||||
| Unweighted sample size | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Weighted average item score | .57 | .55 | .53 | .55 | .53 | .54 | .54 | .48 | .54 |
| Weighted average R biserial/polyserial | .47 | .46 | .50 | .50 | .51 | .52 | .38 | .48 | .46 |
| Weighted alpha reliability | .71 | .70 | .76 | .79 | .77 | .77 | .62 | .68 | .74 |
| Weighted proportion of students attempting last item | .94 | .98 | .92 | .84 | .96 | .94 | .88 | .98 | .92 |
Last updated 24 July 2024 (SK)