NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → IRT Parameters for the Mathematics Assessments → IRT Parameters for Items in the Measurement Scale, Grade 8 Mathematics Combined National and State Main Assessment, by Item and Block: 2009

NAEP Technical DocumentationIRT parameters for items in the measurement scale, grade 8 mathematics combined national and state main assessment, by item and block: 2009

Block	Item	NAEP ID	aj	bj	cj	dj1	dj2	dj3	dj4
† Not applicable; c parameters are not estimated for generalized partial credit models, and d parameters are not estimated for two-parameter or three-parameter logistic models. NOTE: For item j, aj represents the discriminatory power of the item, bj represents a location parameter related to item difficulty, cj represents the guessing parameter, and dji represents the category threshold parameter for category i. The c parameter value is exactly zero for items scaled with the two-parameter logistic model. For item j, dji may not sum to zero because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 Mathematics Assessment.
M3	1	M149801	0.48	-1.72	0.14	†	†	†	†
	4	M150101	0.83	-0.60	0.24	†	†	†	†
	12	M150901	0.88	0.55	†	†	†	†	†
	13	M151001	0.93	0.35	0.23	†	†	†	†
M4	2	M151401	0.79	0.89	0.06	†	†	†	†
	4	M151601	0.87	1.47	†	-0.56	0.56	†	†
	12	M152401	0.98	0.78	0.06	†	†	†	†
M5	12	M047101	0.98	0.08	0.15	†	†	†	†
	17	M047901	1.16	1.33	†	†	†	†	†
	4	M085501	1.12	0.56	0.17	†	†	†	†
	3	M085601	1.00	-0.43	0.26	†	†	†	†
M6	1	M140401	1.13	-0.72	0.11	†	†	†	†
	5	M140801	1.41	0.52	0.20	†	†	†	†
	7	M141001	1.22	-0.09	0.14	†	†	†	†
M7	1	M163801	0.64	-2.65	0.16	†	†	†	†
	5	M164401	1.23	-0.83	0.08	†	†	†	†
	9	M168701	0.53	-0.08	†	-0.83	0.83	†	†
M8	10	M120901	0.91	0.64	0.04	†	†	†	†
	7	M165101	0.82	1.17	0.15	†	†	†	†
M9	15	M1657CL	0.51	0.97	†	-0.87	3.08	-4.11	1.91
	9	M166801	0.50	0.71	0.06	†	†	†	†
M10	2	M142101	0.83	-0.42	0.22	†	†	†	†
	6	M142501	1.32	1.52	0.11	†	†	†	†
	12	M143101	0.80	0.33	0.18	†	†	†	†
M11	5	M121801	0.55	0.17	0.49	†	†	†	†
	13	M167301	1.15	0.94	0.15	†	†	†	†
M12	2	M152801	0.61	-0.04	0.10	†	†	†	†
	11	M153701	1.08	0.23	0.02	†	†	†	†

Printer-friendly Version