NAEP Analysis and Scaling - Block-Level Descriptive Statistics as Defined After Scaling, Grade 4 U.S. History National Assessment, by Public and Nonpublic School Sessions: 2010

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Block-Level Descriptive Statistics as Defined After Scaling, Grade 4 U.S. History National Assessment, by Public and Nonpublic School Sessions: 2010

NAEP Technical DocumentationBlock-level descriptive statistics as defined after scaling, grade 4 U.S. history national assessment, by public and nonpublic school sessions: 2010
Statistic	Type of school¹	Block H3	Block H4	Block H5	Block H6	Block H7	Block H8
† Not applicable. ¹Nonpublic school sample includes only private and Catholic schools. NOTE: The "weighted average item score" of polytomous items are standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items. The "weighted proportion of students attempting last item" is equal to 1 - (Percent not responding to last item /100). 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), 2010 U.S. History Assessment.
Number of scaled items	†	16	16	15	16	16	16
Unweighted sample size	Public	2,200	2,200	2,200	2,200	2,100	2,100
Unweighted sample size	Nonpublic	200	100	200	200	200	200
Weighted average item score	Public	.42	.46	.48	.42	.48	.49
Weighted average item score	Nonpublic	.50	.55	.56	.52	.53	.56
Weighted average polyserial	Public	.49	.51	.52	.54	.45	.51
Weighted average polyserial	Nonpublic	.45	.49	.56	.51	.43	.51
Weighted alpha reliability	Public	.74	.71	.72	.74	.65	.74
Weighted alpha reliability	Nonpublic	.67	.64	.73	.69	.59	.69
Weighted proportion of students attempting last item	Public	.72	.83	.90	.78	.80	.77
Weighted proportion of students attempting last item	Nonpublic	.85	.95	.97	.94	.92	.88

Last updated 05 January 2016 (GF)