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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 Civics National Assessment, by Block and Item Type: 2018
NAEP Technical DocumentationOverall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Civics National Assessment, by Block and Item Type: 2018
| Statistic | Item type | Block C1 | Block C2 | Block C3 | Block C4 | Block C5 | Block C6 | Block C7 |
|---|---|---|---|---|---|---|---|---|
| Number of scaled items | Total | 24 | 26 | 26 | 24 | 23 | 19 | 18 |
| Multiple choice | 18 | 21 | 22 | 18 | 19 | 6 | 7 | |
| Dichotomously scored constructed-response | 1 | 2 | 2 | 2 | 1 | 6 | 3 | |
| Polytomously scored constructed-response | 5 | 3 | 2 | 4 | 3 | 7 | 8 | |
| Unweighted sample size | † | 1,800 | 1,800 | 1,800 | 1,800 | 1,800 | 1,700 | 1,800 |
| Weighted average item score1 | † | .58 | .56 | .52 | .46 | .50 | .56 | .52 |
| Weighted average polyserial | † | .53 | .56 | .53 | .54 | .49 | .59 | .57 |
| Weighted alpha reliability | † | .82 | .86 | .82 | .81 | .77 | .82 | .82 |
| Weighted proportion of students attempting last item2 | † | .86 | .83 | .87 | .82 | .87 | .79 | .72 |
|
† 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: DBA = Digitally based assessment. Item statistics in this table are described on the page Blocks of Items. The block naming conventions used in this table are described in the document 2018 Block Naming Conventions in Data Products and TDW  .SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2018 Civics Assessment. | ||||||||
| Statistic | Item type | Block C3 | Block C4 | Block C5 | Block C6 | Block C7 | Block C8 | Block C9 | Block C10 |
|---|---|---|---|---|---|---|---|---|---|
| Number of scaled items | Total | 20 | 17 | 19 | 19 | 17 | 18 | 19 | 19 |
| Multiple choice | 15 | 13 | 15 | 14 | 13 | 15 | 16 | 15 | |
| Dichotomously scored constructed-response | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | |
| Polytomously scored constructed-response | 5 | 4 | 3 | 5 | 4 | 3 | 2 | 4 | |
| Unweighted sample size | † | 1,800 | 1,700 | 1,800 | 1,700 | 1,700 | 1,800 | 1,700 | 1,800 |
| Weighted average item score1 | † | .57 | .49 | .47 | .54 | .49 | .55 | .53 | .55 |
| Weighted average polyserial | † | .50 | .50 | .53 | .57 | .52 | .54 | .57 | .58 |
| Weighted alpha reliability | † | .74 | .71 | .77 | .82 | .73 | .76 | .78 | .82 |
| Weighted proportion of students attempting last item2 | † | .89 | .84 | .86 | .85 | .83 | .90 | .95 | .86 |
| † 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: PBA = Paper-based assessment. Item statistics in this table are described on the page Blocks of Items. The block naming conventions used in this table are described in the document 2018 Block Naming Conventions in Data Products and TDW .SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2018 Civics Assessment. | |||||||||
Last updated 17 January 2023 (ML)