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NAEP Analysis and Scaling → Estimation of NAEP Score Scales → Item Response Theory Parameters → Mathematics Assessment Item Response Theory Parameters → IRT Parameters for Items in the Data Analysis, Statistics, and Probability Scale, by Block and Item, Grade 8 Mathematics Combined National and State Main Assessment: 2005

NAEP Technical DocumentationIRT parameters for items in the data analysis, statistics, and probability scale, by block and item, grade 8 mathematics combined national and state main assessment: 2005
Block Item NAEP ID aj bj cj dj1 dj2 dj3 dj4
† Not applicable; c parameters are not estimated for generalized partial credit 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 is 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), 2005 Mathematics Assessment.
M3 6 M047301 0.89 -2.09 0.00 † † † †
M4 7 M046601 1.08 -1.10 0.00 † † † †
19 M047801 1.09 0.61 0.11 † † † †
M5 9 M047001 0.93 -0.77 0.10 † † † †
18 M053101 0.55 1.46 † 0.04 0.41 -0.45 †
M6 4 M140701 0.60 0.07 0.12 † † † †
13 M141601 0.94 0.78 0.00 † † † †
M7 2 M143701 0.55 -1.68 0.12 † † † †
13 M144801 0.85 -0.25 0.12 † † † †
M8 4 M0732CL 0.44 -1.20 † 1.85 0.54 -0.78 -1.61
8 M092201 1.04 0.20 0.11 † † † †
13 M092601 0.73 1.52 † -0.55 0.55 † †
M9 3 M013131 0.64 0.91 0.00 † † † †
8 M073501 0.14 4.92 0.00 † † † †
11 M072901 0.52 -0.70 † -0.46 0.46 † †
18 M093801 0.27 0.07 † -3.39 2.54 0.86 †
M10 10 M142901 0.94 0.71 0.13 † † † †
11 M143001 0.46 0.06 0.10 † † † †
M11 10 M106601 0.70 -1.33 0.10 † † † †
14 M107001 1.14 0.46 0.33 † † † †
16 M107201 1.05 1.99 0.11 † † † †
M12 6 M110401 0.62 0.13 0.02 † † † †
7 M110501 0.64 0.76 † 0.43 -0.43 † †
8 M110601 0.49 -2.44 0.07 † † † †

Last updated 19 February 2009 (GF)

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