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NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → Science Assessment IRT Parameters → IRT Parameters for Items in the Univariate Scale, Grade 4 Science Combined National and State Assessment, by Item and Block: 2015
NAEP Technical DocumentationIRT Parameters for Items in the Univariate Scale, Grade 4 Science Combined National and State Assessment, by Item and Block: 2015
| Block | Item | NAEP ID | aj | bj | cj | dj1 | dj2 | dj3 | dj4 |
|---|---|---|---|---|---|---|---|---|---|
| S3 | 1 | K080101 | 0.86 | -0.29 | 0.34 | † | † | † | † |
| 2 | K080001 | 0.46 | 0.72 | 0.16 | † | † | † | † | |
| 3 | K077602 | 0.50 | 0.25 | † | 0.85 | -0.38 | -0.47 | † | |
| 4 | K077603 | 1.06 | 1.65 | 0.33 | † | † | † | † | |
| 5 | K080301 | 0.36 | -0.10 | 0.10 | † | † | † | † | |
| 6 | K080302 | 0.87 | 1.00 | 0.42 | † | † | † | † | |
| 7 | K080404 | 0.60 | 1.18 | † | 0.82 | -0.82 | † | † | |
| 8 | K080501 | 1.01 | -0.06 | 0.28 | † | † | † | † | |
| 9 | K080502 | 0.59 | 1.18 | 0.26 | † | † | † | † | |
| 10 | K153001 | 0.62 | 1.36 | † | 0.87 | -0.87 | † | † | |
| 11 | K080601 | 1.15 | 0.80 | 0.20 | † | † | † | † | |
| 12 | K153101 | 1.00 | 0.91 | 0.21 | † | † | † | † | |
| 13 | K153102 | 0.33 | 4.09 | 0.00 | † | † | † | † | |
| 14 | K080801 | 0.67 | -1.49 | 0.40 | † | † | † | † | |
| 15 | K106701 | 0.53 | 0.81 | † | 0.99 | -0.99 | † | † | |
| 16 | K081001 | 1.33 | 0.26 | 0.24 | † | † | † | † | |
| 17 | K081201 | 1.14 | 0.93 | 0.16 | † | † | † | † | |
| S4 | 1 | K079001 | 1.33 | -0.18 | 0.34 | † | † | † | † |
| 2 | K078801 | 0.48 | 0.27 | 0.26 | † | † | † | † | |
| 3 | K078701 | 1.02 | 0.94 | 0.07 | † | † | † | † | |
| 4 | K078902 | 0.61 | 1.30 | † | 2.36 | -2.36 | † | † | |
| 5 | K084301 | 0.57 | 0.45 | 0.00 | † | † | † | † | |
| 6 | K084302 | 0.79 | 0.09 | 0.00 | † | † | † | † | |
| 7 | K153201 | 0.67 | -1.52 | 0.49 | † | † | † | † | |
| 8 | K153301 | 0.72 | 0.01 | † | 0.75 | -0.75 | † | † | |
| 9 | K079301 | 0.42 | 0.05 | 0.11 | † | † | † | † | |
| 10 | K079501 | 0.58 | 1.34 | † | 0.50 | -0.50 | † | † | |
| 11 | K086401 | 0.60 | -2.72 | 0.12 | † | † | † | † | |
| 12 | K079801 | 1.17 | 1.19 | 0.12 | † | † | † | † | |
| 14 | K084401 | 0.85 | -0.16 | 0.20 | † | † | † | † | |
| 15 | K153401 | 0.93 | -0.46 | 0.57 | † | † | † | † | |
| S5 | 1 | K086101 | 0.74 | -0.79 | 0.37 | † | † | † | † |
| 2 | K081501 | 1.16 | 0.85 | 0.21 | † | † | † | † | |
| 3 | K081601 | 0.60 | 2.03 | † | -0.25 | 0.25 | † | † | |
| 4 | K087301 | 0.42 | -0.51 | † | 1.32 | -1.32 | † | † | |
| 5 | K081801 | 0.46 | 1.53 | † | 0.36 | -0.36 | † | † | |
| 7 | K082101 | 1.54 | 1.49 | 0.15 | † | † | † | † | |
| 8 | K082102 | 1.40 | 1.41 | 0.09 | † | † | † | † | |
| 9 | K082103 | 0.23 | 1.81 | 0.15 | † | † | † | † | |
| 10 | K0855CL | 0.51 | -0.80 | † | 0.45 | 0.14 | -0.59 | † | |
| 11 | K082301 | 0.91 | 0.79 | 0.09 | † | † | † | † | |
| 12 | K153501 | 0.92 | 1.16 | 0.22 | † | † | † | † | |
| 13 | K153502 | 0.96 | 0.93 | 0.27 | † | † | † | † | |
| 14 | K082501 | 0.37 | -0.18 | † | 1.28 | -1.28 | † | † | |
| 15 | K082601 | 1.99 | 1.04 | 0.24 | † | † | † | † | |
| 16 | K084202 | 0.71 | 2.22 | † | 0.07 | -0.07 | † | † | |
| 17 | K084208 | 1.04 | 0.85 | 0.25 | † | † | † | † | |
| S6 | 1 | K107301 | 0.66 | -2.05 | 0.21 | † | † | † | † |
| 2 | K086501 | 1.34 | 1.00 | 0.39 | † | † | † | † | |
| 3 | K108001 | 1.41 | 0.64 | 0.22 | † | † | † | † | |
| 4 | K086601 | 0.31 | 1.51 | 0.25 | † | † | † | † | |
| 5 | K086602 | 0.63 | 0.97 | 0.23 | † | † | † | † | |
| 6 | K107902 | 0.59 | 0.77 | † | 0.62 | -0.62 | † | † | |
| 7 | K086801 | 0.94 | -0.25 | 0.45 | † | † | † | † | |
| 8 | K0869CL | 0.51 | -0.89 | † | 0.99 | -0.85 | -0.15 | † | |
| 9 | K081701 | 0.93 | -0.28 | 0.13 | † | † | † | † | |
| 10 | K076501 | 0.52 | 0.19 | † | 0.81 | -0.81 | † | † | |
| 11 | K087402 | 0.27 | 1.37 | † | 3.31 | -0.11 | -3.20 | † | |
| 12 | K087501 | 1.13 | 0.77 | 0.27 | † | † | † | † | |
| 13 | K109102 | 0.44 | 1.99 | † | 1.08 | -1.08 | † | † | |
| 14 | K108701 | 0.69 | -1.38 | 0.27 | † | † | † | † | |
| 15 | K087701 | 1.25 | 0.68 | 0.19 | † | † | † | † | |
| 16 | K087901 | 1.29 | -1.03 | 0.33 | † | † | † | † | |
| S7 | 1 | K165501 | 0.99 | -1.51 | 0.23 | † | † | † | † |
| 2 | K165101 | 1.03 | -0.01 | 0.37 | † | † | † | † | |
| 3 | K162301 | 0.80 | -2.21 | 0.17 | † | † | † | † | |
| 4 | K1642CL | 0.44 | -0.63 | † | 1.97 | 1.73 | -3.71 | † | |
| 5 | K162201 | 0.78 | -2.53 | 0.15 | † | † | † | † | |
| 6 | K163401 | 0.83 | -1.81 | 0.34 | † | † | † | † | |
| 7 | K160701 | 1.11 | 0.84 | 0.15 | † | † | † | † | |
| 8 | K159001 | 1.46 | 0.84 | 0.23 | † | † | † | † | |
| 9 | K164801 | 1.01 | -2.25 | 0.13 | † | † | † | † | |
| 10 | K164901 | 0.47 | -1.60 | † | 1.36 | -1.36 | † | † | |
| 11 | K164701 | 0.80 | 1.68 | 0.26 | † | † | † | † | |
| 12 | K162501 | 1.35 | 0.77 | 0.31 | † | † | † | † | |
| 13 | K160601 | 0.81 | 1.10 | 0.13 | † | † | † | † | |
| 14 | K1597CL | 0.53 | -0.05 | † | 0.75 | 1.13 | -1.87 | † | |
| 15 | K162401 | 0.66 | -3.71 | 0.27 | † | † | † | † | |
| S8 | 1 | K078601 | 0.80 | -1.96 | 0.13 | † | † | † | † |
| 2 | K109901 | 0.64 | 0.05 | 0.26 | † | † | † | † | |
| 3 | K077501 | 0.44 | -0.90 | † | 0.50 | -0.50 | † | † | |
| 5 | K106501 | 0.93 | 2.36 | 0.09 | † | † | † | † | |
| 6 | K077701 | 0.43 | -0.29 | † | -0.25 | 0.25 | † | † | |
| 7 | K108501 | 1.20 | 1.48 | 0.23 | † | † | † | † | |
| 8 | K109301 | 1.04 | 1.28 | 0.22 | † | † | † | † | |
| 9 | K078102 | 0.33 | 1.33 | † | -0.03 | -2.01 | 2.05 | † | |
| 10 | K078103 | 0.25 | 3.14 | 0.17 | † | † | † | † | |
| 11 | K082401 | 1.08 | 1.32 | 0.41 | † | † | † | † | |
| 12 | K082402 | 1.51 | 1.52 | 0.27 | † | † | † | † | |
| 13 | K1097CL | 0.40 | 1.24 | † | 3.08 | 1.15 | -3.57 | -0.67 | |
| 14 | K078201 | 1.12 | 0.34 | 0.20 | † | † | † | † | |
| 15 | K078301 | 0.55 | 0.54 | † | 0.76 | -0.76 | † | † | |
| 16 | K085801 | 1.34 | -0.21 | 0.20 | † | † | † | † | |
| S9 | 2 | K088001 | 0.95 | -0.10 | 0.35 | † | † | † | † |
| 3 | K088201 | 0.65 | 1.31 | 0.38 | † | † | † | † | |
| 4 | K088202 | 1.23 | 1.77 | 0.22 | † | † | † | † | |
| 5 | K088301 | 0.28 | -4.00 | 0.25 | † | † | † | † | |
| 6 | K088302 | 0.53 | -2.23 | 0.00 | † | † | † | † | |
| 7 | K088401 | 0.58 | 1.61 | † | 1.97 | 0.88 | 0.41 | -3.26 | |
| 8 | K084601 | 0.58 | -0.29 | 0.25 | † | † | † | † | |
| 9 | K109501 | 1.32 | 0.66 | 0.24 | † | † | † | † | |
| 10 | K109401 | 0.34 | -2.15 | 0.18 | † | † | † | † | |
| 11 | K109402 | 0.70 | 1.62 | † | -1.45 | 1.45 | † | † | |
| 12 | K088951 | 0.65 | -1.30 | 0.17 | † | † | † | † | |
| 13 | K089001 | 1.11 | 1.44 | 0.33 | † | † | † | † | |
| 14 | K1537CL | 0.47 | -0.82 | † | 0.32 | 1.83 | -2.15 | † | |
| 15 | K089201 | 0.80 | 1.30 | 0.27 | † | † | † | † | |
| 16 | K078401 | 0.65 | 1.40 | 0.19 | † | † | † | † | |
| S10 | 1 | K153801 | 0.39 | -3.43 | 0.28 | † | † | † | † |
| 2 | K083701 | 0.68 | -0.07 | 0.16 | † | † | † | † | |
| 3 | K0829CL | 0.48 | -0.51 | † | 2.37 | 1.74 | -2.07 | -2.04 | |
| 4 | K153901 | 0.94 | 2.67 | 0.27 | † | † | † | † | |
| 5 | K154001 | 0.34 | 2.02 | † | 0.37 | -0.37 | † | † | |
| 6 | K154151 | 0.77 | 0.40 | 0.23 | † | † | † | † | |
| 7 | K083301 | 0.63 | -0.08 | 0.25 | † | † | † | † | |
| 8 | K083302 | 0.95 | 1.31 | 0.31 | † | † | † | † | |
| 9 | K083501 | 0.73 | -0.90 | 0.26 | † | † | † | † | |
| 10 | K083502 | 0.46 | 0.61 | † | 1.57 | -1.57 | † | † | |
| 11 | K081301 | 1.48 | 1.84 | 0.32 | † | † | † | † | |
| 12 | K083601 | 0.51 | -0.03 | 0.20 | † | † | † | † | |
| 13 | K085301 | 1.08 | 0.92 | 0.16 | † | † | † | † | |
| 14 | K085302 | 0.49 | 1.13 | † | 1.07 | -1.07 | † | † | |
| 15 | K083402 | 0.48 | 1.28 | † | 0.76 | 1.19 | -1.95 | † | |
| 16 | K081401 | 1.25 | 0.98 | 0.32 | † | † | † | † | |
| 17 | K154201 | 1.08 | -0.07 | 0.28 | † | † | † | † | |
| S11 | 1 | K161301 | 0.55 | -1.96 | 0.13 | † | † | † | † |
| 2 | K1603CL | 0.45 | 0.47 | 0.00 | † | † | † | † | |
| 3 | K165401 | 0.94 | -1.82 | 0.15 | † | † | † | † | |
| 4 | K159101 | 0.71 | 0.48 | 0.20 | † | † | † | † | |
| 5 | K163901 | 0.89 | -2.35 | 0.16 | † | † | † | † | |
| 6 | K164001 | 1.14 | -1.59 | 0.22 | † | † | † | † | |
| 7 | K164101 | 0.98 | -1.83 | 0.26 | † | † | † | † | |
| 8 | K1633CL | 0.89 | 0.67 | † | 1.34 | -1.34 | † | † | |
| 9 | K161901 | 0.86 | -0.14 | 0.22 | † | † | † | † | |
| 10 | K160001 | 1.88 | 1.20 | 0.13 | † | † | † | † | |
| 11 | K160101 | 0.90 | 0.56 | 0.33 | † | † | † | † | |
| 12 | K160201 | 0.69 | 0.88 | 0.25 | † | † | † | † | |
| 13 | K165301 | 0.85 | -0.06 | 0.20 | † | † | † | † | |
| 14 | K162001 | 0.91 | 0.24 | 0.30 | † | † | † | † | |
| † 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 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), 2015 Science Assessment. | |||||||||
Last updated 17 November 2021 (ML)