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NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → Mathematics Assessment IRT Parameters → IRT Parameters for the Algebra and Functions Scale, by Block and Item, Grade 8 Mathematics National Main Assessment (Accommodations Permitted [R3]): 2000

NAEP Technical DocumentationIRT parameters for the algebra and functions scale, by block and item, grade 8 mathematics national main assessment (accommodations permitted [R3]): 2000

Block	Item	NAEP ID	aj	bj	cj	dj1	dj2	dj3	dj4
M3	1	M093001	0.77	1.17	0.24	†	†	†	†
	4	M093301	1.17	0.59	0.12	†	†	†	†
	6	M093501	0.61	0.90	0.00	0.30	-0.30	†	†
	8	M093701	0.99	1.92	0.12	†	†	†	†
M4	10	M018301	0.88	-0.66	0.16	†	†	†	†
	14	M018701	1.70	0.18	0.27	†	†	†	†
	15	M018801	1.37	0.58	0.31	†	†	†	†
	20	M019301	1.49	0.89	0.18	†	†	†	†
M5	1	M067001	1.22	0.61	0.32	†	†	†	†
	3	M066201	0.93	-1.22	0.22	†	†	†	†
	4	M066301	0.61	-2.28	0.00	†	†	†	†
	6	M066501	0.53	-0.60	0.00	-0.16	0.16	†	†
	7	M066601	0.38	-0.93	0.00	-0.64	0.64	†	†
	8	M067201	0.55	0.90	0.00	-1.54	1.54	†	†
	8	M067202	2.25	0.82	0.44	†	†	†	†
	9	M067301	1.04	0.43	0.13	†	†	†	†
	10	M067401	0.77	1.15	0.13	†	†	†	†
M6	1	M019701	0.48	-2.04	0.00	†	†	†	†
	8	M020401	0.64	-0.52	0.00	†	†	†	†
	14	M021201	0.84	0.34	0.00	†	†	†	†
M7	1	M068101	0.87	-0.73	0.19	†	†	†	†
	2	M067701	0.73	-1.63	0.17	†	†	†	†
	4	M067901	0.62	-0.60	0.00	-1.45	1.45	†	†
M8	1	M012231	0.58	-3.09	0.19	†	†	†	†
	11	M013231	0.94	1.43	0.11	†	†	†	†
	18	M013731	1.04	1.23	0.12	†	†	†	†
M9	3	M052501	0.80	0.91	0.13	†	†	†	†
M10	7	M086101	0.72	0.71	0.20	†	†	†	†
	8	M086201	1.08	0.61	0.23	†	†	†	†
	9	M086301	0.49	0.01	0.00	1.15	1.87	-1.49	-1.53
M11	15	M047601	1.41	0.19	0.09	†	†	†	†
	16	M047701	1.05	1.47	0.25	†	†	†	†
M12	5	M091701	1.16	-0.65	0.26	†	†	†	†
	7	M091801	1.20	0.77	0.16	†	†	†	†
	9	M092001	0.24	1.57	0.00	-0.88	-2.19	0.40	2.67
M13	6	M051701	2.33	0.43	0.25	†	†	†	†
	10	M052101	0.95	0.35	0.00	†	†	†	†
M15	2	M075301	1.26	-0.26	0.00	1.27	-1.27	†	†
	4	M075501	1.62	0.21	0.16	†	†	†	†
	6	M0757CL	0.88	0.92	0.00	†	†	†	†
† Not applicable; the number of item parameters estimated depends upon the IRT model used for scaling. 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 is the category threshold parameter for category i. The c-parameter value is exactly zero for items scaled with the two-parameter logistic model or the generalized partial credit model. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2000 Mathematics Assessment.

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