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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 Science Scale, Grade 4 Science Combined National and State Main Assessment, by Item and Block: 2009

NAEP Technical DocumentationIRT parameters for items in the univariate science scale, grade 4 science 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: Univariate scale. 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 Science Assessment.
S3 1 K080101 0.74 -0.27 0.28
2 K080001 0.53 0.74 0.17
3 K077602 0.50 0.33 0.83 -0.45 -0.38
4 K077603 1.06 1.63 0.33
5 K080301 0.36 0.07 0.14
6 K080302 0.90 0.96 0.41
7 K080404 0.61 1.20 0.83 -0.83
8 K080501 0.98 -0.02 0.28
9 K080502 0.45 0.92 0.21
10 K153001 0.62 1.37 0.85 -0.85
11 K080601 1.14 0.61 0.23
12 K153101 0.88 1.02 0.19
13 K153102 0.36 3.74
14 K080801 0.71 -1.07 0.43
15 K106701 0.52 0.92 0.96 -0.96
16 K081001 1.35 0.31 0.22
17 K081201 1.11 0.94 0.16
S4 1 K079001 1.38 -0.10 0.35
2 K078801 0.50 0.40 0.28
3 K078701 1.07 0.96 0.08
4 K078902 0.59 1.51 2.43 -2.43
5 K084301 0.62 0.44
6 K084302 0.78 0.16
7 K153201 0.70 -1.25 0.53
8 K153301 0.74 -0.04 0.91 -0.91
9 K079301 0.40 0.08 0.10
10 K079501 0.56 1.41 0.45 -0.45
11 K086401 0.60 -2.65 0.15
12 K079801 1.17 1.16 0.12
14 K084401 0.86 -0.21 0.18
15 K153401 0.84 -0.69 0.50
S5 1 K086101 0.73 -0.71 0.36
2 K081501 1.11 0.94 0.20
3 K081601 0.57 2.14 -0.37 0.37
4 K087301 0.45 -0.41 1.28 -1.28
5 K081801 0.45 1.55 0.27 -0.27
6 K081901 0.95 2.53 0.17
7 K082101 1.53 1.53 0.15
8 K082102 1.33 1.47 0.09
9 K082103 0.35 1.89 0.24
10 K0855CL 0.46 -0.53 0.61 0.33 -0.95
11 K082301 0.99 0.79 0.09
12 K153501 1.02 1.15 0.23
13 K153502 0.95 0.98 0.27
14 K082501 0.36 -0.07 1.34 -1.34
15 K082601 2.06 1.12 0.25
16 K084202 0.73 2.27 0.06 -0.06
17 K084208 1.02 0.80 0.24
S6 1 K107301 0.65 -1.96 0.22
2 K086501 1.39 1.05 0.39
3 K108001 1.43 0.68 0.20
4 K086601 0.38 1.55 0.29
5 K086602 0.73 1.00 0.26
6 K107902 0.56 0.82 0.58 -0.58
7 K086801 0.89 -0.27 0.42
8 K0869CL 0.49 -0.87 1.05 -0.91 -0.14
9 K081701 0.88 -0.33 0.13
10 K076501 0.52 0.22 0.84 -0.84
11 K087402 0.27 1.50 3.51 -0.14 -3.38
12 K087501 1.16 0.78 0.28
13 K109102 0.46 1.95 1.04 -1.04
14 K108701 0.66 -1.40 0.25
15 K087701 1.32 0.72 0.20
16 K087901 1.22 -1.02 0.29
S7 1 K076001 0.92 -1.04 0.17
2 K085001 0.79 -1.57 0.25
3 K076801 0.56 -0.37 0.21
4 K076802 0.73 -0.54 0.27
5 K076302 0.81 0.53
6 K076601 0.57 -0.21 0.21
7 K080703 0.62 2.28 0.48 1.01 -1.49
8 K076901 0.58 1.07 -0.15 0.15
9 K076401 0.57 3.03 0.38
10 K153601 0.68 0.39 0.12 -0.12
11 K087101 0.80 0.88 -0.34 0.34
12 K077001 1.23 1.24 0.22
13 K077201 0.61 -0.38 0.08 -0.08
14 K077301 0.94 0.04 0.43
15 K085101 0.82 -0.36 0.32
16 K080401 1.53 1.26 0.38
S8 1 K078601 0.82 -1.87 0.15
2 K109901 0.68 0.12 0.27
3 K077501 0.43 -0.87 0.47 -0.47
5 K106501 0.94 2.44 0.08
6 K077701 0.42 -0.18 -0.27 0.27
7 K108501 1.21 1.49 0.23
8 K109301 1.24 1.27 0.24
9 K078102 0.34 1.40 0.05 -1.82 1.77
10 K078103 0.36 2.85 0.22
11 K082401 1.15 1.39 0.42
12 K082402 1.64 1.51 0.28
13 K1097CL 0.40 1.25 3.10 1.08 -3.69 -0.48
14 K078201 1.04 0.40 0.19
15 K078301 0.55 0.60 0.80 -0.80
16 K085801 1.36 -0.23 0.19
S9 2 K088001 0.96 -0.07 0.31
3 K088201 0.63 1.29 0.38
4 K088202 1.18 1.83 0.22
5 K088301 0.30 -3.94 0.26
6 K088302 0.33 -0.55 2.01 -2.01
7 K088401 0.61 1.59 1.93 0.81 0.44 -3.18
8 K084601 0.60 -0.34 0.25
9 K109501 1.22 0.68 0.24
10 K109401 0.37 -1.92 0.21
11 K109402 0.72 1.66 -1.50 1.50
13 K089001 1.42 1.57 0.35
14 K1537CL 0.46 -0.76 0.18 1.92 -2.11
15 K089201 0.86 1.35 0.28
16 K078401 0.70 1.30 0.19
S10 1 K153801 0.38 -3.21 0.30
2 K083701 0.73 0.04 0.16
3 K0829CL 0.62 0.39 2.03 -0.87 -1.16
4 K153901 0.99 2.76 0.27
5 K154001 0.35 1.98 0.26 -0.26
7 K083301 0.71 0.07 0.30
8 K083302 1.04 1.36 0.31
9 K083501 0.77 -0.90 0.26
10 K083502 0.47 0.66 1.55 -1.55
11 K081301 1.78 1.65 0.31
12 K083601 0.54 -0.04 0.20
13 K085301 1.14 0.93 0.17
14 K085302 0.51 1.19 1.05 -1.05
15 K083402 0.49 1.34 0.82 0.98 -1.80
16 K081401 1.38 1.04 0.34
17 K154201 1.04 0.00 0.27
S11 1 K089601 0.35 -2.22 0.15
2 K154301 1.28 1.29 0.15
3 K085201 0.58 -0.51 0.21
4 K089502 0.76 -0.18
5 K088501 0.54 0.16 0.16
6 K089701 0.85 0.02 0.28
7 K089702 0.74 1.58 0.36
8 K106301 0.63 2.15 1.31 2.16 -1.00 -2.47
9 K076201 0.46 1.93 -0.37 0.37
10 K106601 1.23 0.49 0.25
11 K106603 0.89 1.11 -0.22 0.22
12 K106604 0.93 0.48 0.29
13 K107601 0.86 1.53 0.22
14 K080901 0.60 -1.16
15 K107201 0.86 -0.15 0.28
16 K107001 0.99 -0.73 0.20

Last updated 03 June 2016 (GF)