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NAEP Analysis and Scaling → Estimation of NAEP Score Scales → Item Response Theory Parameters → Science Assessment Item Response Theory Parameters → IRT Parameters for Items in the Life Science Scale, by Block and Item, Grade 4 Science Combined National and State Main Assessment: 2005

NAEP Technical DocumentationIRT parameters for items in the life science scale, by block and item, grade 4 science combined national and state main assessment: 2005
Block Item NAEP ID aj bj cj dj1 dj2 dj3
† 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 is 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), 2005 Science Assessment.
S3 3 K031003 0.51 2.40 † 1.90 -1.90 †
4 K031004 0.57 -0.68 0.00 † † †
5 K031005 0.62 0.47 0.00 † † †
6 K031006 0.47 -0.01 † 0.24 -0.24 †
7 K031007 0.65 0.09 0.00 † † †
2 K0310CL 0.19 0.37 † -4.42 -0.48 4.90
S5 4 K090101 0.38 -2.16 0.29 † † †
7 K098101 0.81 0.80 0.27 † † †
1 K099101 0.29 -1.91 0.33 † † †
S8 15 K102801 1.16 1.01 0.26 † † †
16 K102901 1.35 0.93 0.27 † † †
12 K103001 0.94 1.02 0.13 † † †
13 K103101 0.50 4.31 0.00 † † †
14 K103201 2.08 2.03 0.38 † † †
2 K103301 1.23 2.26 0.24 † † †
3 K103401 1.23 -0.01 0.25 † † †
4 K103601 1.36 -0.10 0.24 † † †
5 K103701 0.80 0.59 0.22 † † †
9 K103801 1.09 0.69 0.25 † † †
10 K103901 0.42 1.52 0.00 † † †
6 K104001 1.08 -0.93 0.33 † † †
11 K104101 0.98 0.76 0.21 † † †
1 K104201 0.42 -2.54 0.23 † † †
8 K104301 1.33 0.79 0.34 † † †
S9 1 K060201 1.44 -0.32 0.48 † † †
2 K060202 1.04 -0.27 0.39 † † †
3 K060203 1.05 1.68 † 0.90 -0.90 †
4 K060204 0.77 1.06 † -0.35 0.35 †
5 K060205 1.06 -0.26 0.27 † † †
6 K060206 0.94 0.98 † -0.46 0.46 †
7 K060207 0.49 0.72 † 0.90 0.06 -0.96
8 K060301 0.59 -0.38 0.00 † † †
9 K060302 1.12 0.04 0.40 † † †
S10 1 K031701 0.71 -0.08 0.31 † † †
9 K0325CL 0.38 -0.23 † -0.40 -1.52 1.92
10 K032601 0.82 1.35 † 0.72 -0.72 †
11 K032602 0.79 1.54 0.00 † † †
S11 11 K092201 0.72 1.21 † 0.40 -0.40 †
5 K098001 0.58 -1.91 0.29 † † †
1 K099201 0.43 -2.04 0.30 † † †
S12 1 K034601 0.81 0.78 0.45 † † †
2 K034701 0.67 2.33 0.28 † † †
12 K060701 1.56 -0.49 0.40 † † †
14 K060901 0.45 1.44 † 0.38 -0.38 †
S13 2 K035501 0.32 -1.26 0.27 † † †
6 K035901 0.74 1.98 0.00 † † †
S14 1 K037001 0.92 1.13 0.17 † † †
2 K037101 0.30 -1.81 0.19 † † †
3 K037201 1.43 0.97 0.33 † † †
13 K061801 0.70 -1.43 0.26 † † †
S15 5 K062301 0.99 0.22 0.36 † † †
9 K062701 0.47 -0.77 0.36 † † †
14 K063001 0.71 1.78 † -0.23 0.23 †
Last updated 27 July 2009 (JL)

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