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NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → Writing Assessment IRT Parameters → IRT Parameters for Items in the Single Overall Writing Scale, Grade 8 National , By Item and Block: 2011
| Block | Item | NAEP ID | aj | bj | cj | dj1 | dj2 | dj3 | dj4 | dj5 |
|---|---|---|---|---|---|---|---|---|---|---|
| † 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), 2011 Writing Assessment. |
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| W1 | 1 | W015801 | 1.07 | -0.10 | † | 2.45 | 1.03 | -0.41 | -1.23 | -1.85 |
| W2 | 1 | W015901 | 1.37 | -0.13 | † | 2.12 | 1.04 | -0.17 | -1.10 | -1.89 |
| W3 | 1 | W016101 | 1.17 | -0.04 | † | 2.20 | 1.05 | -0.13 | -1.31 | -1.81 |
| W4 | 1 | W018801 | 1.23 | -0.14 | † | 2.06 | 1.07 | -0.01 | -1.23 | -1.89 |
| W5 | 1 | W018901 | 1.19 | -0.05 | † | 2.29 | 1.20 | -0.20 | -1.26 | -2.04 |
| W6 | 1 | W019001 | 1.07 | -0.25 | † | 1.99 | 0.90 | 0.00 | -1.11 | -1.77 |
| W7 | 1 | W016901 | 1.36 | -0.14 | † | 1.99 | 1.01 | -0.11 | -1.17 | -1.72 |
| W8 | 1 | W017101 | 1.40 | 0.10 | † | 2.09 | 0.89 | -0.30 | -0.95 | -1.71 |
| W9 | 1 | W017201 | 1.03 | 0.11 | † | 2.28 | 1.25 | -0.21 | -1.44 | -1.89 |
| W10 | 1 | W017401 | 1.07 | -0.01 | † | 1.90 | 1.47 | 0.04 | -1.43 | -1.98 |
| W11 | 1 | W018301 | 1.45 | -0.03 | † | 2.17 | 1.14 | -0.40 | -1.10 | -1.82 |
| W12 | 1 | W018501 | 1.49 | -0.01 | † | 2.31 | 1.25 | -0.36 | -1.14 | -2.06 |
| W13 | 1 | W018601 | 1.22 | -0.01 | † | 2.16 | 1.11 | -0.04 | -1.18 | -2.05 |
| W14 | 1 | W018701 | 1.08 | 0.36 | † | 2.42 | 1.19 | 0.01 | -1.19 | -2.43 |
| W15 | 1 | W016401 | 1.31 | 0.29 | † | 2.20 | 1.00 | 0.03 | -1.18 | -2.05 |
| W16 | 1 | W016501 | 1.48 | 0.26 | † | 1.94 | 0.78 | -0.17 | -1.02 | -1.53 |
| W17 | 1 | W016601 | 1.57 | 0.12 | † | 1.99 | 0.86 | -0.16 | -1.01 | -1.67 |
| W18 | 1 | W016801 | 1.68 | 0.18 | † | 2.04 | 0.86 | -0.15 | -1.05 | -1.70 |
| W19 | 1 | W017501 | 1.36 | 0.16 | † | 1.67 | 0.85 | -0.04 | -1.01 | -1.48 |
| W20 | 1 | W017601 | 1.30 | -0.15 | † | 1.83 | 0.91 | -0.13 | -1.02 | -1.60 |
| W21 | 1 | W017801 | 1.31 | 0.14 | † | 2.18 | 0.91 | -0.14 | -1.13 | -1.82 |
| W22 | 1 | W018001 | 1.62 | 0.15 | † | 2.21 | 0.88 | -0.23 | -1.13 | -1.73 |
Last updated 01 July 2014 (GF)
