Skip to main content

Table of Contents | Search Technical Documentation | References

HomeTDWNAEP Analysis and ScalingEstimation of NAEP Score ScalesNAEP Assessment IRT ParametersReading Assessment IRT ParametersIRT Parameters for Items in the Literary Subscale, Grade 12 Reading Combined National and State Assessment, By Item and Block: 2013
NAEP Technical DocumentationIRT parameters for items in the literary subscale, grade 12 reading combined national and state assessment, by item and block: 2013
Block Item NAEP ID aj bj cj dj1 dj2 dj3  dj4  dj5 
† 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 value 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), 2013 Reading Assessment.
R1 1 R059601 0.56 -0.05 .17
2 R059602 0.63 -0.70 .27
3 R059603 0.76 -0.95 .20
4 R059604 0.82 -1.87
5 R059610 0.36 -0.41 -0.06 -0.25 0.31
6 R059606 0.69 -0.97 0.22 -0.22
7 R059605 0.65 0.51 0.85 -0.85
8 R059608 0.55 -1.19 .27
9 R059609 0.84 -1.98 .23
10 R059607 0.51 -1.35 -0.07 0.07
R2 1 R069801 0.41 -1.59 2.54 -2.54
2 R069802 0.79 -0.44 .14
3 R069803 1.35 -1.26 .21
4 R069804 0.98 -0.51 0.85 -0.85
5 R069805 0.62 -0.48 .25
6 R069806 0.54 -0.56 1.25 0.39 -1.64
7 R069807 1.13 -1.03 .30
8 R069808 0.96 -1.42 .20
9 R069809 0.83 -1.20 .30
10 R069810 0.50 -0.38 0.11 -0.11
R5 1 R061601 1.41 -0.82 .43
2 R061602 0.72 -0.65 -0.05 0.05
3 R061603 1.11 -1.42 .34
4 R061604 0.68 -1.05 1.16 -1.16
5 R061605 1.28 0.04 .29
6 R061606 0.73 0.56 0.11 -0.11
7 R061607 0.75 -0.02 0.91 0.47 -1.38
8 R061608 1.27 1.35
9 R061609 1.40 1.02 .22
R6 1 R078901 0.97 0.61 .18
2 R078902 0.83 -1.30 .24
3 R078903 0.58 -0.26 0.31 -0.31
4 R078904 1.15 1.01 .25
5 R078905 0.57 0.56 1.20 -0.91 -0.30
6 R078906 1.11 0.17 .20
7 R078907 0.78 0.02
8 R078908 0.24 -0.27 .22
9 R078909 1.35 -0.13 .25
10 R078910 1.46 -0.44 .32

Last updated 21 May 2017 (DC)