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NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Age 13 Mathematics Long-Term Trend National Assessment, by Block: 2020
NAEP Technical DocumentationOverall Descriptive Statistics for Item Blocks as Defined After Scaling, Age 13 Mathematics Long-Term Trend National Assessment, by Block: 2020
| Statistic | Block M1 | Block M2 | Block M3 | Block M4 | Block M5 | Block M6 |
|---|---|---|---|---|---|---|
| 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), 2020 Mathematics Long-Term Trend Assessment. | ||||||
| Total number of scaled items | 24 | 22 | 26 | 33 | 22 | 22 |
| Number of multiple-choice items | 19 | 17 | 18 | 25 | 18 | 17 |
| Number of dichotomously scored CR items | 5 | 5 | 8 | 8 | 4 | 5 |
| Number of polytomously scored CR items | 0 | 0 | 0 | 0 | 0 | 0 |
| Unweighted sample size | 4,400 | 4,500 | 4,500 | 4,500 | 4,400 | 4,400 |
| Weighted average item score | .67 | .70 | .66 | .68 | .64 | .68 |
| Weighted average R biserial/polyserial | .62 | .64 | .67 | .63 | .65 | .66 |
| Weighted alpha reliability | .86 | .85 | .90 | .90 | .85 | .86 |
| Weighted proportion of students attempting last item | .86 | .82 | .73 | .66 | .87 | .89 |
Last updated 30 April 2024 (PG)