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NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → Mathematics Assessment IRT Parameters → IRT Parameters for Items in the Measurement Subscale, Grade 8 Mathematics Combined National and State Assessment, By Item and Block: 2013
NAEP Technical DocumentationIRT parameters for items in the measurement subscale, grade 8 mathematics combined national and state assessment, by item and block: 2013
Block Item NAEP ID aj bj cj dj1 dj2 dj3  dj4 
† Not applicable; c parameters are not estimated for the two-parameter logistic model or 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 assumed to be exactly zero and is not estimated 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), 2013 Mathematics Assessment.
MC 1 M149801 0.49 -1.75 .14 † † † †
4 M150101 0.93 -0.29 .41 † † † †
12 M150901 0.86 0.54 † † † † †
13 M151001 0.82 0.21 .19 † † † †
MD 2 M151401 0.93 0.96 .09 † † † †
4 M151601 0.86 1.44 † -0.53 0.53 † †
12 M152401 0.96 0.67 .07 † † † †
ME 1 M221201 1.17 0.22 .37 † † † †
2 M221202 1.47 0.49 .35 † † † †
4 M221204 0.63 0.92 † 1.43 -1.43 † †
MF 1 M140401 1.14 -0.74 .11 † † † †
5 M140801 1.51 0.51 .20 † † † †
7 M141001 1.30 -0.06 .16 † † † †
MG 1 M163801 0.59 -2.88 .19 † † † †
5 M164401 1.24 -0.92 .06 † † † †
9 M168701 0.53 -0.06 † -0.88 0.88 † †
MH 1 M236101 0.46 0.52 .05 † † † †
3 M234601 0.78 -0.43 .11 † † † †
14 M236401 0.84 -1.22 .17 † † † †
MI 3 M235001 0.75 -1.67 .12 † † † †
8 M237601 1.00 -0.69 .19 † † † †
14 M238401 1.46 0.39 .10 † † † †
MJ 2 M222501 0.89 0.05 .21 † † † †
9 M223201 0.88 1.76 .29 † † † †
MK 5 M121801 0.78 0.39 .53 † † † †
13 M167301 1.48 0.89 .18 † † † †
ML 2 M231401 1.12 0.74 .51 † † † †
6 M233101 1.03 -0.74 .10 † † † †
13 M339601 0.50 -0.20 .12 † † † †
Last updated 21 May 2017 (DC)
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