NAEP Analysis and Scaling - IRT Parameters for the Change and Continuity in American Democracy: Ideas, Institutions, Practices, and Controversies Scale, by Block and Item, Grade 4 U.S. History National Main Assessment (Accommodations Not Permitted [R

NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → U.S. History Assessment IRT Parameters → IRT Parameters for the Change and Continuity in American Democracy: Ideas, Institutions, Practices, and Controversies Scale, by Block and Item, Grade 4 U.S. History National Main Assessment (Accommodations Not Permitted [R2]): 2001

NAEP Technical DocumentationIRT parameters for the change and continuity in American democracy: Ideas, institutions, practices, and controversies scale, by block and item, grade 4 U.S. history national main assessment (accommodations not permitted [R2]): 2001
Block	Item	NAEP ID	a_j	b_j	c_j	d_j1	d_j2
H3	5	H028501	0.82	2.15	0.19	†	†
	Cluster: 6,7	H0286CL	0.24	2.08	0.00	0.85	-0.85
	11	H028901	0.86	0.35	0.25	†	†
	14	H029101	0.25	2.36	0.28	†	†
H4	7	H054701	0.90	1.39	0.20	†	†
	8	H054801	0.51	0.47	0.00	0.84	-0.84
	14	H055401	0.92	0.10	0.21	†	†
H5	4	H056001	0.61	1.72	0.19	†	†
	6	H056201	0.81	0.58	0.20	†	†
	7	H056301	1.83	1.41	0.16	†	†
	9	H056501	0.66	1.02	0.22	†	†
H6	7	H032001	0.37	1.09	0.20	†	†
	8	H032002	0.47	1.38	0.31	†	†
	13	H032501	0.79	0.83	0.15	†	†
	14	H032502	0.64	0.08	0.19	†	†
	15	H032503	0.71	1.29	0.00	0.14	-0.14
H7	5	H057601	0.84	1.38	0.20	†	†
	9	H058001	0.63	0.79	0.18	†	†
	10	H058101	0.49	1.58	0.29	†	†
	11	H058201	1.04	1.42	0.25	†	†
	15	H058601	0.39	0.85	0.00	0.44	-0.44
H8	7	H034701	0.32	0.27	0.24	†	†
	8	H034702	0.49	4.17	0.00	1.07	-1.07
	9	H034801	0.82	1.13	0.22	†	†
	10	H034901	0.55	-1.24	0.22	†	†
	15	H035301	0.53	1.44	0.19	†	†
	16	H035401	0.58	0.86	0.26	†	†
† Not applicable; the number of item parameters estimated depends upon the IRT model used for scaling. NOTE: For item j, a_j represents the discriminatory power of the item, b_j represents a location parameter related to item difficulty, c_j represents the guessing parameter, and d_ji 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), 2001 U.S. History Assessment.

Last updated 15 July 2008 (KL)