NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Items as Defined After Scaling, Age 13 Mathematics Long-Term Trend Assessment, By Block: 2012
| Statistic | Item type | Block M1 | Block M2 | Block M3 | Block M4 | Block M5 | Block M6 |
|---|---|---|---|---|---|---|---|
| † Not applicable. 1 The "Weighted proportion of students attempting last item" is equal to 1 - (Percent not responding to last item /100). NOTE: Item statistics in this table are described on the page Blocks of Items. Block M4 is an historical block. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2012 Mathematics Long-Term Trend Assessment. |
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| Number of scaled items | Total | 24 | 22 | 26 | 36 | 23 | 22 |
| Multiple choice | 19 | 17 | 18 | 28 | 18 | 17 | |
| Dichtomously scored constructed response | 5 | 5 | 8 | 8 | 5 | 5 | |
| Polytomously scored constructed response | 0 | 0 | 0 | 0 | 0 | 0 | |
| Unweighted sample size | † | 4,200 | 4,100 | 4,000 | 4,200 | 4,100 | 4,100 |
| Weighted average item score | † | 0.68 | 0.74 | 0.69 | 0.70 | 0.64 | 0.71 |
| Weighted average polyserial | † | 0.60 | 0.62 | 0.64 | 0.57 | 0.61 | 0.64 |
| Weighted alpha reliability | † | 0.83 | 0.82 | 0.88 | 0.88 | 0.83 | 0.84 |
| Weighted proportion of students attempting last item1 | † | 0.92 | 0.91 | 0.81 | 0.69 | 0.91 | 0.95 |
Last updated 15 January 2014 (JL)