NAEP Analysis and Scaling - Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Music National Main Assessment: 2008

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Music National Main Assessment: 2008

NAEP Technical DocumentationOverall descriptive statistics for item blocks as defined after scaling, grade 8 arts (music) assessment: 2008
Statistic	Item type	Block U3	Block U4	Block U5	Block U6
† 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), 2008 Arts (Music) Assessment.
Number of scaled items	Total	15	17	15	15
	Multiple choice	5	7	6	3
	Dichotomously scored constructed response	4	4	3	2
	Polytomously scored constructed response	6	6	6	10
Unweighted sample size	†	2,000	2,000	1,900	1,900
Weighted average item score	†	0.38	0.48	0.53	0.31
Weighted average polyserial	†	0.54	0.51	0.55	0.51
Weighted alpha reliability	†	0.68	0.68	0.71	0.71
Weighted proportion of students attempting last item¹	†	0.91	0.99	0.96	0.98

Last updated 28 September 2011 (JL)