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NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Reading Combined National and State Assessment, by Block: 2019
NAEP Technical DocumentationOverall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Reading Combined National and State Assessment, by Block: 2019
| Statistic | Block R1 | Block R2 | Block R3 | Block R4 | Block R6 | Block R7 | Block R8 | Block R9 | Block R10 | Block R11 | Block R12 | Block R14 | Block R15 | Block R17 | Block R18 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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). Weights are applied to reflect sampling design. | |||||||||||||||
| CR = Constructed response. Item statistics in this table are described on the page Blocks of Items. | |||||||||||||||
| U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Reading Assessment. | |||||||||||||||
| Total number of scaled items | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 8 | 10 | 10 | 11 |
| Number of multiple-choice items | 5 | 6 | 7 | 6 | 7 | 7 | 6 | 5 | 5 | 6 | 5 | 3 | 3 | 5 | 4 |
| Number of dichotomously scored CR items | 1 | 0 | 2 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 2 | 2 | 4 | 1 | 4 |
| Number of polytomously scored CR items | 4 | 4 | 1 | 3 | 3 | 2 | 3 | 5 | 5 | 3 | 3 | 3 | 3 | 4 | 3 |
| Unweighted sample size | 19,300 | 18,900 | 19,000 | 19,200 | 18,900 | 19,500 | 18,900 | 18,900 | 19,000 | 19,200 | 18,900 | 18,900 | 19,100 | 18,900 | 18,900 |
| Weighted average item score | .63 | .62 | .61 | .49 | .69 | .77 | .72 | .62 | .62 | .57 | .63 | .55 | .48 | .59 | .67 |
| Weighted average R biserial/polyserial | .68 | .68 | .67 | .64 | .74 | .76 | .77 | .70 | .68 | .66 | .70 | .61 | .62 | .66 | .69 |
| Weighted alpha reliability | .74 | .75 | .71 | .72 | .77 | .73 | .77 | .76 | .75 | .73 | .75 | .61 | .69 | .71 | .74 |
| Weighted proportion of students attempting last item | .89 | .91 | .97 | .76 | .97 | .94 | .97 | .97 | .94 | .92 | .84 | .80 | .93 | .82 | .93 |
Last updated 05 October 2023 (SK)