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Statistic | Item type | Block M1 | Block M2 | Block M3 | Block M4 | Block M5 | Block M6 | Block M7 | Block M8 | Block M9 | Block M10 |
---|---|---|---|---|---|---|---|---|---|---|---|
Number of scaled items | Total | 14 | 16 | 14 | 20 | 19 | 20 | 16 | 13 | 20 | 20 |
Multiple choice | 2 | 4 | 3 | 16 | 15 | 16 | 12 | 3 | 15 | 16 | |
Dichotomously scored constructed-response | 5 | 6 | 5 | 1 | 2 | 0 | 1 | 6 | 2 | 3 | |
Polytomously scored constructed-response | 7 | 6 | 6 | 3 | 2 | 4 | 3 | 4 | 3 | 1 | |
Unweighted sample size | † | 29,200 | 29,300 | 29,600 | 29,400 | 29,300 | 29,200 | 29,200 | 30,500 | 31,300 | 30,900 |
Weighted average item score1 | † | .35 | .37 | .39 | .48 | .51 | .53 | .52 | .36 | .52 | .63 |
Weighted average polyserial | † | .66 | .65 | .58 | .57 | .59 | .53 | .59 | .57 | .63 | .64 |
Weighted alpha reliability | † | .78 | .79 | .71 | .81 | .80 | .77 | .78 | .67 | .85 | .85 |
Weighted proportion of students attempting last item2 | † | .77 | .81 | .87 | .82 | .84 | .88 | .85 | .71 | .76 | .87 |
† Not applicable. 1 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. 2 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), 2017 Mathematics Assessment. |