Skip to main content
Skip Navigation

Table of Contents  |  Search Technical Documentation  |  References

NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → Mathematics Assessment IRT Parameters → IRT Parameters for the Measurement Scale, by Block and Item, Grade 8 Mathematics State Assessment (Accommodations Permitted [R3]): 2000
NAEP Technical DocumentationIRT parameters for the measurement scale, by block and item, grade 8 mathematics state assessment (accommodations permitted [R3]): 2000
Block Item NAEP ID aj bj cj dj1 dj2 dj3 dj4
M3 3 M093201 0.51 1.33 0.16
7A M093601 0.90 1.49 0.00 1.17 -1.17
M4 2 M017501 0.33 -3.31 0.14
8 M018101 0.54 -0.70 0.07
18 M019101 1.22 1.63 0.16
19 M019201 1.40 1.56 0.14
M6 7A M020301 1.08 -0.33 0.00
M7 9A M068008 0.49 1.89 0.00 0.14 -0.14
M8 2A M012331 0.80 -1.45 0.14
14A M013331 0.99 -1.25 0.15
M9 1 M052301 1.83 0.75 0.25
M10 1 M085501 0.94 0.77 0.12
2 M085601 1.16 0.20 0.24
M11 12 M047101 1.15 0.26 0.15
13 M047201 0.74 -1.00 0.08
18A M047901 1.15 1.44 0.00
M13 2A M051301 0.39 -2.47 0.00
11A M052201 0.68 0.96 0.00 0.67 -0.38 -0.29
M14 1A M072801 0.76 0.54 0.34
6A M073301 1.25 1.45 0.28
M15 1A M075201 0.62 -0.45 0.26
3A M075401 0.50 0.15 0.00 1.02 -1.02
5A M075601 0.60 0.21 0.00 -0.75 0.75
9A M076001 0.55 1.48 0.00 -1.42 0.31 1.11
† Not applicable; the number of item parameters estimated depends upon the IRT model used for scaling.
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 or the generalized partial credit model.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2000 Mathematics Assessment.

Last updated 14 July 2008 (KL)

Printer-friendly Version