NAEP Analysis and Scaling - Overall Descriptive Statistics for Items as Defined After Scaling, Grade 12 Geography National Assessment: 2010

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Items as Defined After Scaling, Grade 12 Geography National Assessment: 2010

NAEP Technical DocumentationOverall descriptive statistics for items as defined after scaling, grade 12 geography national assessment: 2010
Statistic	Item type	Block G3	Block G4	Block G5	Block G6	Block G7	Block G8	Block G9
† Not applicable. NOTE: The "weighted average item score" of polytomous items are standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items. The "weighted proportion of students attempting last item" is equal to 1 - (Percent not responding to last item /100). 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), 2010 Geography Assessment.
Number of scaled items	Total	16	17	17	16	16	16	21
	Multiple choice	11	12	13	12	11	10	13
	Dichtomously scored constructed response	0	1	0	0	0	1	3
	Polytomously scored constructed response	5	4	4	4	5	5	5
Unweighted sample size	†	2,500	2,500	2,500	2,500	2,500	2,500	2,400
Weighted average item score	†	.55	.51	.46	.56	.48	.37	.50
Weighted average polyserial	†	.57	.52	.53	.54	.55	.57	.58
Weighted alpha reliability	†	.72	.73	.74	.74	.73	.72	.79
Weighted proportion of students attempting last item	†	.95	.89	.93	.95	.65	.76	1.00

Last updated 05 January 2016 (GF)