Block-level Descriptive Statistics as Defined After Scaling, Grade 8 Civics National Assessment, by Public and Nonpublic School Sessions: 2014

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NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Block-level Descriptive Statistics as Defined After Scaling, Grade 8 Civics National Assessment, by Public and Nonpublic School Sessions: 2014

NAEP Technical Documentation
Block-level Descriptive Statistics as Defined After Scaling, Grade 8 Civics National Assessment, by Public and Nonpublic School Sessions: 2014
Block-level descriptive statistics as defined after scaling, grade 8 civics national assessment, by public and nonpublic school sessions: 2014
Statistic	Type of school¹	Block C3	Block C4	Block C5	Block C6	Block C7	Block C8	Block C9	Block C10
Number of scaled items	†	20	17	18	19	18	19	19	19
Unweighted sample size	Public	2,000	2,000	2,000	2,000	2,000	2,000	2,000	2,000
Unweighted sample size	Nonpublic	270	270	270	260	260	270	240	250
Weighted average item score²	Public	.55	.49	.46	.54	.48	.56	.52	.55
Weighted average item score²	Nonpublic	.65	.56	.54	.59	.53	.65	.59	.64
Weighted average polyserial	Public	.49	.49	.54	.55	.49	.49	.55	.57
Weighted average polyserial	Nonpublic	.48	.48	.51	.54	.50	.45	.53	.62
Weighted alpha reliability	Public	.72	.68	.76	.79	.69	.70	.77	.81
Weighted alpha reliability	Nonpublic	.67	.63	.71	.76	.70	.58	.73	.81
Weighted proportion of students attempting last item³	Public	.93	.87	.89	.89	.85	.92	.95	.91
Weighted proportion of students attempting last item³	Nonpublic	.94	.91	.97	.95	.91	.97	.99	.92
† Not applicable. ¹ Nonpublic school sample includes only private schools, including Catholic schools. ₂The "Weighted average item score" of polytomous items is standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items. ³ The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item /100). NOTE: Item statistics in this table are described on the page Blocks of Items. In 2014, grades 4 and 12 were not assessed. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2014 Civics Assessment.

Last updated 23 May 2021 (SK)

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