NAEP Analysis and Scaling - Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Geography National Main Assessment (Accommodations Not Permitted [R2]): 2001

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Geography National Main Assessment (Accommodations Not Permitted [R2]): 2001

NAEP Technical DocumentationOverall descriptive statistics for item blocks as defined after scaling, grade 8 geography national main assessment (accommodations not permitted [R2]): 2001
Statistic	Item type	Block G3	Block G4	Block G5	Block G6	Block G7	Block G8	Block G9
Number of scaled items	Total	17	16	17	16	14	17	25
	Multiple choice	12	11	11	12	10	12	15
	Dichotomously scored constructed response	0	1	1	0	0	2	3
	Polytomously scored constructed response	5	4	5	4	4	3	7
Unweighted sample size		2,200	2,200	2,200	2,200	2,200	2,200	2,300
Weighted average item score		0.50	0.53	0.50	0.41	0.45	0.68	0.51
Weighted average polyserial		0.58	0.50	0.60	0.49	0.58	0.61	0.53
Weighted alpha reliability		0.76	0.67	0.78	0.69	0.74	0.76	0.80
Weighted proportion of students attempting last item¹		0.98	0.96	0.97	0.90	0.73	0.94	0.99
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), 2001 Geography Assessment.

Last updated 10 July 2008 (FW)