NAEP Analysis and Scaling - Overall Descriptive Statistics for Items as Defined After Scaling, Grade 8 Writing Combined National and State Main Assessment: 2007

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Items as Defined After Scaling, Grade 8 Writing Combined National and State Main Assessment: 2007

NAEP Technical DocumentationOverall descriptive statistics for items as defined after scaling, grade 8 writing combined national and state main assessment: 2007
Statistic	Item type	All items
† Not applicable. 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	Total	20
	Multiple choice	0
	Dichotomously scored constructed response	0
	Polytomously scored constructed response	20
Unweighted sample size		139,900
Weighted average iem score		0.55
Weighted average polyserial		0.92
Weighted alpha reliability		†
Weighted proportion of students attempting last item		†

Last updated 23 June 2010 (GF)