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NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Item-Level Descriptive Statistics as Defined After Scaling, Grade 8 Writing Combined National and State Main Assessment, by Public and Nonpublic School Sessions: 2007
Item-level descriptive statistics as defined after scaling, grade 8 writing combined national and state main assessment, by public and nonpublic school sessions: 2007
Statistic Type of school All items
† Not applicable.
1 The "Weighted proportion of students attempting last item" is equal to 1 - (Percent not responding to last item /100).
NOTE: Nonpublic-school samples include only Catholic and private schools.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2007 Writing Assessment.
Number of scaled items 20
Unweighted sample size Public 135,100
Nonpublic 3,100
Weighted average item score Public 0.55
Nonpublic 0.63
Weighted average polyserial Public 0.91
Nonpublic 0.90
Weighted alpha reliability Public
Weighted proportion of students attempting last item1 Public

Last updated 07 June 2010 (JL)

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