NAEP Analysis and Scaling - Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Mathematics Combined National and State Main Assessment: 2003

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Mathematics Combined National and State Main Assessment: 2003

NAEP Technical DocumentationOverall descriptive statistics for item blocks as defined after scaling, grade 8 mathematics combined national and state main assessment: 2003
Statistic	Item type	Block M3	Block M4	Block M5	Block M6	Block M7	Block M8	Block M9	Block M10	Block M11	Block M12
Number of scaled items	Total	18	20	18	29	19	18	18	18	19	18
	Multiple choice	12	7	9	21	14	12	10	10	16	15
	Dichotomously scored constructed response	3	5	4	7	3	2	3	7	3	1
	Polytomously scored constructed response	3	8	5	1	2	4	5	1	0	2
Unweighted sample size	†	30,300	30,300	30,500	30,800	30,600	31,100	30,500	30,800	30,200	30,600
Weighted average item score	†	0.54	0.62	0.59	0.65	0.49	0.52	0.48	0.52	0.54	0.55
Weighted average polyserial	†	0.60	0.62	0.62	0.59	0.60	0.60	0.58	0.63	0.58	0.56
Weighted alpha reliability	†	0.76	0.77	0.81	0.85	0.78	0.79	0.80	0.81	0.76	0.75
Weighted proportion of students attempting last item¹	†	0.94	0.70	0.89	0.92	0.90	0.86	0.78	0.86	0.95	0.93
† 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), 2003 Mathematics Assessment.

Last updated 16 February 2009 (GF)