NAEP Analysis and Scaling - Overall Descriptive Statistics for Items as Defined After Scaling, Grade 12 Writing National Main Assessment: 2007

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Items as Defined After Scaling, Grade 12 Writing National Main Assessment: 2007

NAEP Technical DocumentationOverall descriptive statistics for items as defined after scaling, grade 12 writing national 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 ccaled items	Total	20
	Multiple choice	0
	Dichotomously scored constructed response	0
	Polytomously scored constructed response	20
Unweighted sample size		27,900
Weighted average item score		0.59
Weighted average polyserial		0.91
Weighted alpha reliability		†
Weighted proportion of students attempting last item		†

Last updated 07 June 2010 (JL)