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Table of Contents | Search Technical Documentation | References
NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Block-Level Descriptive Statistics as Defined After Scaling, Grade 4 Vocabulary National Assessment, by Block and School Type: 2015
NAEP Technical DocumentationBlock-Level Descriptive Statistics as Defined After Scaling, Grade 4 Vocabulary National Assessment, by Block and School Type: 2015
| Statistic | Type of school1 | Block R14 | Block R15 | Block R16 | Block R17 | Embedded items |
|---|---|---|---|---|---|---|
| Number of scaled items | † | 5 | 6 | 5 | 5 | 20 |
| Unweighted sample size | Public | 3,500 | 3,500 | 3,600 | 3,500 | 4,500 |
| Nonpublic | 400 | 400 | 400 | 400 | 500 | |
| Weighted average item score2 | Public | .58 | .56 | .69 | .53 | .58 |
| Nonpublic | .67 | .64 | .79 | .61 | .65 | |
| Weighted average polyserial | Public | .80 | .72 | .89 | .75 | .62 |
| Nonpublic | .84 | .75 | .97 | .76 | .68 | |
| Weighted alpha reliability | Public | .58 | .57 | .70 | .55 | † |
| Nonpublic | .59 | .60 | .71 | .52 | † | |
| Weighted proportion of students attempting last item3 | Public | .98 | .97 | .98 | .98 | † |
| Nonpublic | .99 | .98 | .99 | .99 | † | |
| † Not applicable. 1 Nonpublic school sample includes only private schools, including Catholic schools. BIE and DoDEA schools are not included in either the public or nonpublic category. 2 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. 3 The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item / 100). NOTE: The embedded items column contains information about all the vocabulary items embedded in the 25-minute reading comprehension blocks. 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), 2015 Reading Assessment. | ||||||
Last updated 09 November 2021 (ML)