NAEP Analysis and Scaling - Block-Level Descriptive Statistics for Public- and Nonpublic-School Sessions as Defined After Scaling, Grade 12 Reading Vocabulary National Assessment: 2009

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Block-Level Descriptive Statistics for Public- and Nonpublic-School Sessions as Defined After Scaling, Grade 12 Reading Vocabulary National Assessment: 2009

NAEP Technical DocumentationBlock-level descriptive statistics for public- and nonpublic-school sessions as defined after scaling, grade 12 reading vocabulary national assessment: 2009
Statistic	Type of school¹	Block R14	Block R15	Block R16	Block R17	Embedded blocks
† Not applicable. # Rounds to zero. ¹ Nonpublic-school sample includes only Catholic and private schools. ² 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. The Embedded Blocks column contains information about all the Reading Vocabulary items embedded within the 25-minute Reading comprehension blocks. The unweighted sample associated with the embedded items is the average unweighted sample across all embedded Reading Vocabulary items. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 Reading Vocabulary Assessment.
Number of scaled items	†	6	5	5	5	26
Unweighted sample size	Public	2,800	2,800	2,400	2,400	5,700
Unweighted sample size	Nonpublic	100.00	100.00	100.00	100.00	200
Weighted average item score	Public	0.67	0.70	0.59	0.64	0.72
Weighted average item score	Nonpublic	0.80	0.78	0.71	0.76	0.78
Weighted average polyserial	Public	0.72	0.80	0.75	0.78	0.61
Weighted average polyserial	Nonpublic	0.82	0.81	0.78	0.83	0.63
Weighted alpha reliability	Public	0.52	0.53	0.47	0.56	†
Weighted alpha reliability	Nonpublic	0.58	0.39	0.45	0.53	†
Weighted proportion of students attempting last item²	Public	1.00	1.00	1.00	1.00	†
Weighted proportion of students attempting last item²	Nonpublic	1.00	1.00	0.96	1.00	†

Last updated 05 January 2016 (GF)