NAEP Analysis and Scaling - Item-Level Descriptive Statistics by Public- and Nonpublic-School Sessions, as Defined After Scaling, Grade 4 Writing Combined National and State Main Assessment: 2002

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Item-Level Descriptive Statistics by Public- and Nonpublic-School Sessions, as Defined After Scaling, Grade 4 Writing Combined National and State Main Assessment: 2002

NAEP Technical DocumentationItem-level descriptive statistics by public- and nonpublic-school sessions, as defined after scaling, grade 4 writing combined national and state main assessment: 2002
Statistic	Type of school¹	All items²
Number of scaled items		20
Unweighted sample size	Public	132,800
Unweighted sample size	Nonpublic	5,400
Weighted average item score	Public	0.51
Weighted average item score	Nonpublic	0.57
Weighted average polyserial	Public	0.90
Weighted average polyserial	Nonpublic	0.86
¹ Nonpublic-school sample includes only Catholic and private schools. ² In NAEP writing assessments, each block contains only one item—a writing prompt to which students respond with a polytomously scored constructed response; therefore, the weighted alpha reliability estimate is not meaningful and does not appear in this table. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2002 Writing Assessment.

Last updated 16 February 2009 (GF)