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NAEP Analysis and ScalingEstimation of NAEP Score ScalesNAEP Assessment IRT ParametersMathematics Assessment IRT Parameters → IRT Parameters for Items in the Measurement and Geometry Subscale, Grade 12 Mathematics National Assessment, by Block and Item: 2019

​​​NAEP Technical DocumentationIRT Parameters for Items in the Measurement and Geometry Subscale, Grade 12 Mathematics National Assessment, by Block and Item: 2019

IRT parameters for items in the measurement and geometry subscale, grade 12 mathematics DBA national assessment, by block and item: 2019
Item NAEP ID a b c d d d d
Not applicable; c parameters are not estimated for the two-parameter logistic or generalized partial credit models, and d parameters are not estimated for the two-parameter or three-parameter logistic models.
DBA = Digitally based assessment. For item j, a represents the discriminatory power of the item, b represents a location parameter related to item difficulty, c represents the guessing parameter, and d 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, d may not sum to zero because of rounding.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Mathematics Assessment.
Block M1
4 M4059MS 0.72 0.35
6 M4252MS 1.18 0.67
8 M428001 1.07 0.81
12 M423601 1.01 1.23 0.08 -0.08
Block M2
1 M094401 1.22 -0.75 0.17
4 M421901 0.98 -0.35 0.16
9 M131701 0.92 1.28 0.29
12 M4240MS 0.19 5.00
15 M428901 0.65 2.53
Block M3
1 M303801 0.70 -0.71 0.19
6 M305301 0.53 -1.02 0.20
10 M304201 1.01 1.23 0.29
13 M305101 1.19 1.21 0.20
16 M198601 1.72 1.50 0.15
17 M305501 1.17 0.21
Block M4
6 M125801 0.79 -0.74 0.22
9 M175001 0.95 0.15 0.27
10 M175002 0.84 1.92 -0.59 1.97 1.22 -2.60
13 M182201 1.90 2.51 0.21
16 M187701 0.63 0.84 -0.60 0.60
Block M5
1 M199501 1.33 0.81 0.26
7 M199601 0.81 0.48 0.21
9 M183801 0.46 2.32 0.12
12 M176601 1.07 0.98 0.15
14 M192801 1.30 -1.03 0.19
16 M196601 1.24 -0.19 0.12
Block M6
3 M186001 0.85 0.24
8 M200001 0.37 -0.22 0.18
11 M194001 0.81 1.97 -0.44 0.44
13 M185001 2.74 1.54 0.13
14 M055801 1.01 -0.77 0.17
Block M7
5 M431801 1.78 -0.17 0.19
6 M194501 0.32 -0.22 0.19
9 M430901 1.30 1.25 0.23
12 M432801 1.13 1.83 0.19
14 M4272CL 0.49 2.48 0.19 -0.19
Block M8
2 M309101 1.60 -0.12 0.18
6 M4314MS 0.40 0.34 0.71 -0.71
9 M199401 1.80 0.67 0.38
13 M434801 0.54 2.53 0.22
Block M9
1 M192701 0.82 0.71 0.16
5 M190501 1.34 1.22 0.16
8 M1943CL 0.88 1.00 -0.11 0.11
14 M174901 1.61 1.56 0.11
16 M1897CL 0.40 2.50 0.68 -0.44 0.81 -1.04
Block M10
1 M307801 0.72 -0.08 0.25
5 M308001 0.91 1.03
7 M308601 1.84 0.23 0.16
9 M310301 1.18 0.61 0.11
15 M189001 0.75 1.85 1.53 -1.53
17 M414101 0.93 1.62 -0.47 0.47
Block M11
3 M021001 0.75 -1.13
6 M306501 1.10 0.28
11 M305801 1.28 0.11 0.11
14 M305701 1.13 0.96 0.19


IRT parameters for items in the measurement and geometry subscale, grade 12 mathematics PBA national assessment, by block and item: 2019
ItemNAEP IDabcdddd
Not applicable; c parameters are not estimated for the two-parameter logistic or generalized partial credit models, and d parameters are not estimated for the two-parameter or three-parameter logistic models.
PBA = Paper-based assessment. For item j, a represents the discriminatory power of the item, b represents a location parameter related to item difficulty, c represents the guessing parameter, and d 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, d may not sum to zero because of rounding.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Mathematics Assessment.
Block M1
1M1928010.76-1.680.20
7M1780011.041.43-0.270.27
8M1966010.90-0.400.19
Block M2
1M3038010.58-1.150.20
6M3053010.54-1.570.20
10M3042010.661.060.27
13M3051011.311.010.17
Block M3
4M1973010.740.220.18
5M1973020.940.130.15
6M1973031.371.79
7M1973041.511.39
10M1975CL0.731.521.65-0.94-1.280.57
Block M4
1M1842011.090.79
7M1749011.421.640.12
11M1748011.472.460.17-0.17
13M1801011.842.060.14
Block M5
4M1945010.29-0.110.22
6M1857014.071.600.33
7M1857024.251.400.09
8M1857031.201.530.42-1.680.470.79
11M1877010.650.74-0.550.55
Block M6
6M1834011.072.01-0.790.79
9M1750010.84-0.460.23
10M1750021.041.67-0.341.710.88-2.25
13M1822011.952.610.19
Block M7
2M3106010.601.150.28
5M3091011.67-0.270.19
8M3040010.530.31-3.833.83
11M3099010.781.520.26
Block M8
2M1938010.88-0.880.21
4M1986011.931.270.10
6M1882010.751.66-1.070.98-0.630.72
11M1943CL1.230.740.12-0.12
13M1890010.741.571.60-1.60
Block M9
1M1927010.760.690.18
5M1905011.111.050.13
8M1919010.961.210.08-0.350.140.14
12M1989011.061.170.72-0.72
Block M10
3M1785010.601.52-1.381.38
6M1917010.730.530.31-0.31
12M1994011.140.630.34
13M1897CL0.412.410.24-0.100.21-0.35
Block M11
2M1995011.130.600.28
9M1996010.710.130.20
11M1838010.741.970.19
14M1766011.521.130.20
Block M12
3M1860010.860.04
8M2000010.45-0.080.22
11M1940010.612.20-0.210.21
13M1850012.511.470.13
Block M13
4M3058011.290.050.20
7M3055011.10-0.20
9M3065011.120.15
12M3057011.140.820.18
Block M14
1M3078010.62-0.590.20
5M3080010.830.91
7M3086011.39-0.100.15
9M3103011.460.400.17
13M3089011.591.650.17


Last updated 05 December 2023 (SK)