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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 Writing Scale, Grade 12 Writing National Assessment, 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: Assessment at grade 12 was national only. 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 | W019901 | 1.12 | -0.41 | † | 1.82 | 1.10 | 0.03 | -1.03 | -1.93 |
| W2 | 1 | W021801 | 1.22 | -0.50 | † | 2.00 | 1.00 | 0.15 | -1.15 | -2.00 |
| W3 | 1 | W020201 | 1.15 | -0.58 | † | 2.15 | 1.05 | 0.13 | -1.16 | -2.17 |
| W4 | 1 | W022301 | 1.14 | -0.50 | † | 2.05 | 1.22 | 0.13 | -1.06 | -2.34 |
| W5 | 1 | W022601 | 1.41 | -0.31 | † | 2.11 | 1.04 | -0.14 | -1.08 | -1.92 |
| W6 | 1 | W019401 | 1.25 | -0.21 | † | 1.92 | 0.80 | 0.01 | -0.94 | -1.79 |
| W7 | 1 | W019701 | 1.34 | -0.16 | † | 2.04 | 1.12 | -0.15 | -1.04 | -1.96 |
| W8 | 1 | W020001 | 1.41 | -0.07 | † | 1.88 | 1.07 | 0.05 | -1.03 | -1.97 |
| W9 | 1 | W020301 | 1.44 | -0.35 | † | 2.02 | 1.21 | -0.06 | -1.17 | -2.00 |
| W10 | 1 | W021001 | 1.26 | -0.24 | † | 2.20 | 1.17 | -0.01 | -1.23 | -2.11 |
| W11 | 1 | W021701 | 1.27 | -0.14 | † | 2.27 | 1.32 | -0.25 | -1.23 | -2.12 |
| W12 | 1 | W021901 | 1.21 | -0.19 | † | 1.96 | 1.27 | 0.03 | -1.11 | -2.15 |
| W13 | 1 | W022401 | 1.15 | -0.17 | † | 2.05 | 1.16 | -0.05 | -1.15 | -2.01 |
| W14 | 1 | W022701 | 1.21 | -0.20 | † | 2.05 | 1.01 | 0.06 | -0.97 | -2.15 |
| W15 | 1 | W019801 | 1.03 | -0.06 | † | 2.27 | 1.36 | -0.17 | -1.36 | -2.10 |
| W16 | 1 | W020101 | 1.20 | -0.19 | † | 2.21 | 1.14 | -0.03 | -1.19 | -2.12 |
| W17 | 1 | W020601 | 1.33 | -0.07 | † | 1.82 | 1.14 | 0.08 | -1.13 | -1.91 |
| W18 | 1 | W020801 | 1.28 | -0.24 | † | 2.20 | 1.23 | -0.02 | -1.16 | -2.25 |
| W19 | 1 | W020901 | 1.40 | -0.24 | † | 2.07 | 1.01 | 0.06 | -1.12 | -2.01 |
| W20 | 1 | W022001 | 1.26 | -0.10 | † | 2.16 | 1.15 | 0.01 | -1.28 | -2.04 |
| W21 | 1 | W022501 | 1.38 | -0.23 | † | 2.16 | 1.05 | -0.04 | -1.21 | -1.96 |
| W22 | 1 | W022801 | 1.48 | -0.51 | † | 2.01 | 1.17 | 0.15 | -1.31 | -2.02 |
Last updated 01 July 2014 (GF)
