NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Age 17 Mathematics Long-Term Trend Assessment: 2008
| 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. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2008 Mathematics Long-Term Trend Assessment. |
|||||||
| Number of scaled items | Total | 23 | 23 | 29 | 35 | 23 | 23 |
| Multiple choice | 19 | 18 | 23 | 30 | 18 | 18 | |
| Dichotomously scored constructed response | 4 | 5 | 6 | 5 | 5 | 5 | |
| Polytomously scored constructed response | 0 | 0 | 0 | 0 | 0 | 0 | |
| Unweighted sample size | † | 4,800 | 4,800 | 4,800 | 4,800 | 4,700 | 4,800 |
| Weighted average item score | † | 0.68 | 0.70 | 0.67 | 0.70 | 0.66 | 0.68 |
| Weighted average polyserial | † | 0.72 | 0.62 | 0.63 | 0.61 | 0.69 | 0.64 |
| Weighted alpha reliability | † | 0.89 | 0.81 | 0.87 | 0.89 | 0.87 | 0.84 |
| Weighted proportion of students attempting last item1 | † | 0.92 | 0.97 | 0.81 | 0.72 | 0.93 | 0.98 |
Last updated 28 September 2011 (JL)