NAEP Analysis and Scaling - Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 4 Civics National Main Assessment: 2006

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 4 Civics National Main Assessment: 2006

NAEP Technical DocumentationOverall descriptive statistics for item blocks as defined after scaling, grade 4 civics national main assessment: 2006
Statistic	Item type	Block C3	Block C4	Block C5	Block C6	Block C7	Block C8
Number of scaled items	Total	15	15	15	14	15	14
	Multiple choice	11	11	12	10	11	11
	Dichotomously scored constructed response	0	1	0	1	0	0
	Polytomously scored constructed response	4	3	3	3	4	3
Unweighted sample size	†	2,300	2,400	2,300	2,300	2,300	2,300
Weighted average item score	†	0.52	0.47	0.49	0.57	0.53	0.53
Weighted average polyserial	†	0.52	0.53	0.55	0.53	0.56	0.49
Weighted alpha reliability	†	0.69	0.69	0.72	0.68	0.75	0.65
Weighted proportion of students attempting last item¹	†	0.88	0.90	0.88	0.87	0.81	0.91
† Not applicable. ¹ 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), 2006 Civics Assessment.

Last updated 23 June 2010 (GF)