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 Measurement Scale, Grade 8 Mathematics Combined National and State Main Assessment, by Item and Block: 2009
| 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), 2009 Mathematics Assessment. |
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| M3 | 1 | M149801 | 0.48 | -1.72 | 0.14 | † | † | † | † |
| 4 | M150101 | 0.83 | -0.60 | 0.24 | † | † | † | † | |
| 12 | M150901 | 0.88 | 0.55 | † | † | † | † | † | |
| 13 | M151001 | 0.93 | 0.35 | 0.23 | † | † | † | † | |
| M4 | 2 | M151401 | 0.79 | 0.89 | 0.06 | † | † | † | † |
| 4 | M151601 | 0.87 | 1.47 | † | -0.56 | 0.56 | † | † | |
| 12 | M152401 | 0.98 | 0.78 | 0.06 | † | † | † | † | |
| M5 | 12 | M047101 | 0.98 | 0.08 | 0.15 | † | † | † | † |
| 17 | M047901 | 1.16 | 1.33 | † | † | † | † | † | |
| 4 | M085501 | 1.12 | 0.56 | 0.17 | † | † | † | † | |
| 3 | M085601 | 1.00 | -0.43 | 0.26 | † | † | † | † | |
| M6 | 1 | M140401 | 1.13 | -0.72 | 0.11 | † | † | † | † |
| 5 | M140801 | 1.41 | 0.52 | 0.20 | † | † | † | † | |
| 7 | M141001 | 1.22 | -0.09 | 0.14 | † | † | † | † | |
| M7 | 1 | M163801 | 0.64 | -2.65 | 0.16 | † | † | † | † |
| 5 | M164401 | 1.23 | -0.83 | 0.08 | † | † | † | † | |
| 9 | M168701 | 0.53 | -0.08 | † | -0.83 | 0.83 | † | † | |
| M8 | 10 | M120901 | 0.91 | 0.64 | 0.04 | † | † | † | † |
| 7 | M165101 | 0.82 | 1.17 | 0.15 | † | † | † | † | |
| M9 | 15 | M1657CL | 0.51 | 0.97 | † | -0.87 | 3.08 | -4.11 | 1.91 |
| 9 | M166801 | 0.50 | 0.71 | 0.06 | † | † | † | † | |
| M10 | 2 | M142101 | 0.83 | -0.42 | 0.22 | † | † | † | † |
| 6 | M142501 | 1.32 | 1.52 | 0.11 | † | † | † | † | |
| 12 | M143101 | 0.80 | 0.33 | 0.18 | † | † | † | † | |
| M11 | 5 | M121801 | 0.55 | 0.17 | 0.49 | † | † | † | † |
| 13 | M167301 | 1.15 | 0.94 | 0.15 | † | † | † | † | |
| M12 | 2 | M152801 | 0.61 | -0.04 | 0.10 | † | † | † | † |
| 11 | M153701 | 1.08 | 0.23 | 0.02 | † | † | † | † | |
Last updated 03 June 2016 (GF)