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 Data Analysis, Statistics, and Probability Scale, Grade 8 Mathematics Combined National and State Assessments, By Item and Block: 2011

NAEP Technical DocumentationIRT parameters for the data analysis, statistics, and probability scale, grade 8 mathematics combined national and state assessments, by item and block: 2011

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), 2011 Mathematics Assessment.
MC	2	M149901	0.63	0.08	†	0.77	-0.77	†	†
	7	M150401	0.73	-0.27	0.23	†	†	†	†
	10	M150701	0.92	0.18	0.13	†	†	†	†
MD	6	M151801	0.56	-1.32	0.10	†	†	†	†
	11	M152301	0.30	2.29	0.10	†	†	†	†
ME	11	M221901	0.54	0.77	0.10	†	†	†	†
	14	M222201	0.72	1.36	0.13	†	†	†	†
MF	4	M140701	0.61	-0.18	0.14	†	†	†	†
	13	M141601	0.90	0.64	†	†	†	†	†
MG	3	M166001	0.58	-0.87	0.07	†	†	†	†
	14	M167001	0.44	2.92	†	†	†	†	†
MH	4	M170401	0.53	-0.11	0.24	†	†	†	†
	6	M164601	0.54	0.76	†	-4.17	4.17	†	†
MI	5	M168901	1.03	-0.04	†	†	†	†	†
	6	M125301	0.60	-0.43	0.09	†	†	†	†
MJ	6	M222901	1.10	-0.31	0.07	†	†	†	†
	10	M223301	0.42	0.59	†	-0.35	0.35	†	†
	13	M223601	0.95	0.49	0.10	†	†	†	†
MK	8	M171101	1.32	0.17	0.11	†	†	†	†
	11	M162901	0.69	-0.17	†	0.95	-0.95	†	†
	15	M167901	0.51	1.46	†	-1.66	1.66	†	†
ML	6	M153201	0.37	-1.28	†	-1.32	1.32	†	†
	16	M154201	0.48	2.28	0.17	†	†	†	†

Printer-friendly Version