NAEP Analysis and Scaling - Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Reading Combined National and State Main Assessment: 2002

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Reading Combined National and State Main Assessment: 2002

NAEP Technical DocumentationOverall descriptive statistics for item blocks as defined after scaling, grade 8 reading combined national and state main assessment: 2002
Statistic	Item type	Block R3	Block R4	Block R5	Block R6	Block R7	Block R8	Block R9	Block R10	Block R11	Block R13¹
Number of scaled items	Total	10	9	11	12	13	10	9	12	12	13
	Multiple choice	3	2	7	5	6	4	4	4	3	4
	Dichotomously scored constructed response	3	2	3	5	6	2	1	7	8	1
	Polytomously scored constructed response	4	5	1	2	1	4	4	1	1	8
Unweighted sample size	†	20,900	20,800	20,800	20,800	20,900	21,000	20,800	21,000	20,800	21,000
Weighted average item score	†	0.43	0.56	0.70	0.58	0.71	0.55	0.61	0.62	0.70	0.66
Weighted average polyserial	†	0.69	0.60	0.74	0.62	0.72	0.61	0.67	0.60	0.71	0.60
Weighted alpha reliability	†	0.76	0.67	0.78	0.71	0.78	0.69	0.68	0.73	0.80	0.72
Weighted proportion of students attempting last item²	†	0.79	0.83	0.94	0.87	0.83	0.84	.95	0.75	0.84	0.93
† Not applicable. ¹ A 50-minute block. 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. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2002 Reading Assessment.

Last updated 16 February 2009 (GF)