Table of Contents | Search Technical Documentation | References

NAEP Analysis and Scaling → Estimation of NAEP Score Scales → NAEP Assessment IRT Parameters → Science Assessment IRT Parameters → IRT Parameters for Items in the Univariate Scale, Grade 12 Science National Assessment, by Block and Item: 2019

​​​NAEP Technical DocumentationIRT Parameters for Items in the Univariate Scale, Grade 12 Science National Assessment, by Block and Item: 2019

IRT parameters for items in the univariate scale, grade 12 science 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, 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.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
Block S2
1 K217301 0.75 -1.23 0.20
2 K177801 0.45 -1.61 0.25
3 K180201 2.25 1.49 0.05
4 K129601 1.04 0.90 0.49 -0.49
5 K129602 0.67 -0.41 0.24
6 K219001 1.20 0.35 0.25
7 K2196MS 1.44 1.21
8 K215701 0.88 1.16 0.18
9 K215301 0.89 1.29 0.39
10 K177101 0.79 0.30 0.31
11 K177201 0.97 1.03 0.14
12 K174901 0.35 1.57 0.64 -0.64
13 K217801 1.44 1.88 0.13
14 K174801 1.19 0.02 0.24
15 K1754CL 0.63 1.91 -0.01 1.22 -1.21
16 K2203MS 0.64 1.05 -0.58 0.58
17 K2163MS 0.81 -0.60
18 K218201 0.61 0.66 0.22
19 K178501 1.75 0.29 0.21
Block S3
1 K128901 1.16 0.06 0.18
2 K126501 0.59 -0.36 0.32
3 K125901 0.65 -0.40 0.20
4 K133301 0.33 2.69 -0.83 0.72 0.11
5 K1572CL 0.52 2.36 1.86 -1.86
6 K157301 0.98 0.11 0.33
7 K139001 0.75 0.46 1.34 -1.34
8 K143001 1.17 1.37 0.18
9 K126301 1.65 1.19 0.34
10 K126302 1.46 0.59 0.20
11 K126303 0.62 1.50 -0.83 1.70 0.20 -1.07
12 K126304 1.30 0.34
13 K133901 0.77 0.34 0.29
14 K126202 0.76 0.85 -1.67 1.67
15 K132201 0.94 2.48 0.23
16 K157401 0.60 0.58 0.25
17 K157501 0.87 -0.62 0.24
Block S4
1 K137501 0.81 -2.05 0.26
2 K128001 0.25 -1.49 0.25
3 K133801 0.62 1.16 1.27 -0.19 -1.08
4 K128401 1.01 0.30 0.23
5 K128402 0.91 0.94 0.46
6 K128403 0.93 1.64 0.86 -0.70 -0.17
7 K137201 0.81 1.66 -0.82 0.82
8 K137202 1.17 -0.17 0.30
9 K157601 0.92 0.77 0.25
11 K157801 0.92 0.49 0.32
12 K157901 0.71 0.66 0.59 -0.59
13 K126101 1.35 1.94 0.16
14 K126801 0.79 1.12 0.20
15 K144401 0.62 1.23 -0.01 0.01
16 K143701 1.28 1.22 0.14
17 K134801 1.15 0.05 0.26
18 K130201 0.76 0.57 0.30
Block S5
1 K220001 1.47 -0.44 0.30
2 K218001 0.89 1.20 0.27
3 K218101 0.82 0.33 0.28
4 K2191MS 0.43 1.41 -0.73 0.73
5 K219801 1.13 1.28 0.26
6 K220201 0.43 1.25 0.13 -0.13
7 K2202CL 0.76 1.31 0.58 1.58 -2.16
8 K220204 0.88 -0.14 -0.15 0.15
9 K1769MS 1.04 0.71 0.43
10 K216601 0.75 1.05 -1.95 1.95
11 K2169MS 0.54 0.49
12 K177701 1.64 0.91 0.23
13 K176801 1.54 1.29 0.21
14 K2161MS 0.26 1.81 0.96 -0.96
15 K132302 1.03 0.74 0.11
16 K132303 1.26 1.15 0.09
17 K132304 0.70 -0.42 0.25
18 K217501 0.49 0.15 0.16
Block S6
1 K158101 1.78 0.39 0.19
2 K135001 0.73 1.65 0.43 -0.11 -0.32
3 K134701 0.80 1.28 0.23
4 K130901 0.30 -0.37 0.25
5 K139801 0.58 0.37 0.46 -0.46
6 K134401 1.22 1.11 0.25
7 K134901 1.50 0.89 0.28
8 K134902 1.48 1.13 0.21
9 K143801 0.64 2.35 0.47 -0.47
10 K140501 0.64 0.87 0.27
11 K143201 0.82 -0.37 0.31
12 K134501 1.38 0.80 0.13
13 K134502 1.06 0.09 0.29
14 K134503 0.78 -0.13
15 K142801 0.86 0.72 0.36
16 K130701 0.81 1.09 0.28
17 K126001 0.64 1.48 -0.09 0.39 0.33 -0.63
18 K131001 1.11 1.78 0.11 -0.11
Block S7
1 K136601 1.19 2.24 0.39
2 K135601 0.54 -0.48 0.20
3 K131401 0.80 0.48 0.34
4 K136101 0.59 1.16 1.50 -0.21 -1.29
5 K136102 0.59 0.86 0.82 -0.82
6 K136103 0.70 1.74
7 K131901 0.99 1.14 0.09
8 K132701 1.10 1.56 0.10 -0.10
9 K142701 1.02 0.87 0.16
10 K142703 1.27 0.55 0.31
11 K142704 1.13 1.60 0.19
12 K135401 0.72 -0.06
13 K141901 1.35 0.56 0.14
14 K158301 0.68 1.37 0.49 -0.49
15 K137801 0.71 -0.26 0.29
16 K132101 1.29 0.09 0.19
17 K142201 0.88 -0.19 0.15
Block S8
1 K136201 1.21 0.69 0.11
2 K140801 1.00 0.85 0.21
3 K127201 0.58 -0.29 0.61 1.46 -2.07
4 K137101 0.93 -1.45 0.26
5 K137103 1.16 0.82 0.13
6 K136401 0.96 0.97 0.07 -0.07
7 K134001 1.04 0.95 0.24
8 K142401 0.59 0.40 0.30 -0.30
9 K133201 1.84 1.30 0.24
10 K1584CL 0.58 1.35 0.72 -0.06 -0.66
11 K2151MS 0.92 0.97
12 K215113 0.94 1.31 0.34
13 K136901 1.63 1.09 0.35
14 K139201 1.61 1.17 0.36
15 K137001 0.95 0.80 0.27
16 K128801 0.60 -2.09 0.25
17 K143601 1.28 0.36 0.16
18 K143401 1.16 1.16 0.26
19 K129701 0.71 1.80 0.25
Block S9
1 K172401 1.04 0.28 0.28
2 K175501 1.58 0.54 0.22
3 K177301 1.01 -0.11 0.20
4 K173501 0.81 -0.44 0.21
5 K179601 1.25 -0.19 0.35
6 K176401 1.72 1.29 0.46
7 K175901 1.26 0.97 0.17
8 K177001 0.70 1.33 0.29
9 K176601 0.77 0.73 -0.20 0.20
10 K176701 0.87 -0.22 0.15
11 K1776CL 0.69 0.33 0.02 -0.02
12 K175801 1.48 -0.28 0.16
13 K173301 0.59 1.20 1.39 -1.39
14 K175601 0.71 0.72 0.32
15 K173701 1.14 1.34 0.29
16 K177501 1.47 0.55 0.34
17 K180101 1.18 0.89 0.15
18 K176301 1.75 0.81 0.25
19 K174301 1.28 0.73 0.42
Block S10
1 K172301 1.45 0.88 0.45
2 K177401 0.73 0.54 0.21
3 K1745MS 0.73 -0.36
4 K179101 1.19 -0.14 0.32
5 K174401 1.54 1.41 0.19
6 K172901 0.45 0.94 -2.17 2.17
7 K179701 0.74 2.11
8 K179801 0.90 0.01 0.18
9 K179001 1.24 0.04 0.24
10 K178601 1.45 0.89 0.22
11 K175201 1.46 1.01 0.21
12 K173401 1.18 0.49 0.41
13 K172501 0.68 0.31 0.99 -0.99
14 K174601 1.24 1.05 0.33
15 K174701 0.69 0.60 -0.08 0.08
16 K175301 1.18 -1.25 0.27
17 K176001 0.44 1.06 0.22
18 K158001 0.53 -0.02
Block S11
1 K136001 0.55 -0.97 0.23
2 K139301 0.85 -0.35 0.22
3 K141601 0.77 -1.12 0.21
4 K141602 0.78 -1.51 0.26
5 K127701 0.52 0.61 0.97 0.15 -1.12
6 K141001 0.91 0.97 0.19
7 K141002 1.15 0.94 0.18
9 K125802 0.89 1.22 0.37 -0.37
10 K125803 1.05 1.70
11 K144201 1.49 1.07 0.08
12 K144202 0.90 1.38 0.08 -0.08
13 K141701 0.61 1.67 0.44 -0.44
14 K139601 0.67 1.32 0.24
15 K141801 1.85 1.65 0.33
16 K144501 1.14 0.28 0.17
Block S12
1 K143101 1.30 0.33 0.24
2 K133001 0.75 1.67 0.26
3 K142501 0.76 1.37 0.24
4 K129001 0.76 2.44 0.59 -0.59
5 K128701 0.59 1.04 1.34 0.13 -1.64 0.17
7 K133401 0.54 1.23 0.91 -0.91
8 K126601 1.11 1.20 0.34
9 K142901 0.96 1.35 0.16
10 K130002 0.42 0.14 -5.49 4.07 1.42
11 K127401 1.12 -0.69 0.15
13 K127403 0.86 -0.69 0.17
14 K142101 0.72 0.71 0.24
15 K130101 1.10 0.64 0.28
16 K130301 0.68 2.07
17 K158801 1.60 1.25 0.20
18 K158901 0.41 -0.50 0.23
Block S13
1 K135301 0.54 -1.13 0.21
2 K217401 1.44 0.57 0.28
3 K173801 1.13 1.07 0.16
4 K219201 0.97 0.87 0.22
5 K2192MS 0.43 0.03
6 K219901 0.92 1.05
7 K2207MS 0.37 -0.55
8 K218601 0.69 0.88 -0.42 0.42
9 K179201 1.37 1.66 0.20
10 K179301 0.83 1.63 -0.20 0.20
11 K215501 1.35 1.22 0.17
12 K216701 0.72 1.06 0.26
13 K216702 0.90 1.23 0.38 -0.38
14 K2170MS 0.62 1.52
15 K217007 1.22 -0.12 0.19
16 K217008 1.21 0.04 0.25
17 K218401 1.64 0.41 0.26
18 K136701 0.84 0.28 0.28
Block H1
1 K197202 0.99 1.31 0.07 -0.07
2 K1975MS 0.39 -0.66 0.08 -0.08
3 K197503 0.61 -0.19 0.78 -0.78
4 K197601 0.84 1.29
Block H3
1 K1989MS 0.76 -1.41
2 K2209MS 0.81 -1.27
3 K1990CL 0.75 0.42 1.41 0.02 -1.43
4 K1991MS 0.56 2.80
5 K2210CL 0.42 -5.32 2.50 -2.50
6 K199302 0.63 -0.38 -0.05 0.05
8 K1995MS 0.77 2.82
Block I1
1 K1933MS 0.57 1.19
2 K1934MS 0.90 1.63
3 K193501 0.79 0.39 1.23 -1.23
4 K193601 0.60 0.30 -0.83 0.83
5 K1937MS 0.26 -1.18
6 K193801 0.52 -0.20 -0.20 0.20
Block I2
1 K2213MS 0.83 -0.72 0.68 -0.68
2 K221401 0.53 4.13
3 K221501 0.95 -0.92 0.28
4 K221601 0.30 2.73 0.23
5 K221701 0.61 1.66 -0.28 0.28
Block I5
1 K1960MS 1.10 -0.68
2 K196101 0.56 0.88 -1.40 1.40
3 K196201 0.63 1.22 1.87 -1.87
4 K1963MS 0.38 4.16 0.45 -0.45
5 K1964CL 0.60 0.01 1.18 -1.18
6 K1965MS 0.57 -1.22 -1.30 1.30
7&8 K196XCL 0.59 -0.65 0.66 0.62 -0.14 -1.15
9 K1968MS 0.42 -1.50 -4.57 -1.32 5.89
10 K196901 0.76 1.19 0.20 -0.20
11 K197001 0.64 -0.44 -0.63 0.63
12 K197102 0.57 1.99 0.24 -0.24
​
​
IRT parameters for items in the univariate scale, grade 12 science 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, 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.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
Block S3
1K1289011.070.100.24
2K1265010.59-0.310.34
3K1259010.66-0.430.20
4K1333010.402.08-0.890.89
5K1572CL0.412.702.67-2.67
6K1573010.970.070.40
7K1390010.770.731.13-1.13
8K1430010.991.460.17
9K1263012.111.060.34
10K1263021.550.580.20
11K1263030.821.580.690.30-0.99
12K1263041.290.35
13K1339010.910.550.34
14K1262020.810.91-1.251.25
15K1322011.242.050.23
16K1574010.800.530.24
17K1575011.11-0.340.29
Block S4
1K1375010.65-2.280.26
2K1280010.36-1.300.21
3K1338010.671.221.13-1.13
4K1284011.650.380.24
6K1284030.961.510.92-0.76-0.16
7K1372010.901.52
8K1372021.12-0.280.28
9K1576010.750.420.18
11K1578010.780.200.25
12K1579010.750.740.59-0.59
13K1261011.881.570.14
14K1268010.940.900.17
15K1444010.581.320.57-0.57
16K1437011.581.150.12
17K1348011.13-0.040.22
18K1302010.730.970.22
Block S5
1K1399010.224.090.29
2K1296010.921.120.45-0.45
3K1296020.78-0.330.32
4K1439010.900.230.31
5K1439021.502.330.19
6K1439030.631.790.31-0.31
7K1310011.221.35
8K1310021.412.200.23
9K1297010.851.720.29
10K1303010.550.681.00-1.00
11K1323011.661.810.28
12K1323020.880.790.19
13K1323031.531.100.14
14K1323040.61-0.660.28
15K1580010.56-0.22
16K1367010.930.120.24
17K1436011.610.650.25
Block S6
1K1581011.800.420.21
2K1350010.761.900.200.06-0.26
3K1347011.011.080.27
4K1582CL0.681.221.620.13-0.26-1.49
5K1309010.340.190.28
6K1398010.72-0.07
7K1344011.751.200.32
8K1349011.450.970.28
9K1349021.681.160.21
10K1438010.712.530.42-0.42
11K1405010.760.750.29
12K1432010.88-0.370.28
13K1345011.280.900.14
14K1345021.090.150.26
15K1345030.511.180.45-0.45
16K1428011.171.070.36
17K1307011.261.280.31
Block S7
2K1356010.50-0.680.19
3K1314010.790.650.40
4K1361010.621.021.91-0.45-1.46
5K1361020.620.540.98-0.98
6K1361030.710.53
7K1319010.931.200.10
8K1327011.271.630.30-0.30
9K1427010.790.870.17
10K1427031.180.460.30
11K1427041.231.470.16
12K1354010.440.660.10-0.10
13K1419011.580.640.25
14K1583010.671.460.43-0.43
15K1378010.66-0.650.23
16K1321011.440.040.19
17K1422010.90-0.190.20
Block S8
1K1362011.540.690.12
2K1408011.180.750.23
3K1272010.430.171.381.56-0.92-2.03
4K1371010.87-1.700.28
5K1371020.690.65-0.560.320.25
6K1371031.670.660.11
7K1364010.911.110.06-0.06
8K1340011.770.980.23
9K1424010.570.310.34-0.34
10K1332011.941.250.25
11K1584CL0.750.43
12K1376510.440.87-1.05-0.061.12
13K1376521.461.340.36
14K1369011.660.990.37
15K1392011.611.150.31
16K1370011.130.750.28
17K1288010.51-2.160.24
Block S9
1K1724010.950.090.24
2K1755011.550.540.22
3K1773011.160.010.31
4K1735010.82-0.600.19
5K1796011.09-0.300.35
6K1764011.421.180.43
7K1759011.080.790.14
8K1770010.941.110.30
9K1766010.730.61-1.001.00
10K1767010.82-0.380.17
11K1776CL0.42-0.19-3.253.25
12K1758011.35-0.340.16
13K1733010.691.271.31-1.31
14K1756010.740.520.28
15K1737011.191.210.27
16K1775011.910.670.40
17K1801011.340.960.18
18K1763011.850.570.21
19K1743011.630.690.40
Block S10
1K1723011.020.920.43
2K1774010.630.620.22
3K1745011.020.070.25
4K1791011.05-0.410.30
5K1744011.651.470.18
6K1729010.41-0.280.24-2.242.00
7K1797010.431.07
8K1798011.060.060.14
9K1790011.210.010.20
10K1786011.280.700.20
11K1752011.180.770.21
12K1734010.790.370.32
13K1725010.720.101.08-1.08
14K1746011.490.830.31
15K1747011.010.23
16K1753011.18-1.340.33
17K1760010.312.290.29
Block S11
1K1360010.63-0.710.29
2K1393010.87-0.160.31
3K1416010.74-1.390.23
4K1416020.85-1.480.21
5K1277010.680.681.48-1.48
6K1410011.080.930.19
7K1410021.320.870.20
8K1410031.941.510.24
9K1258020.921.680.57-0.57
10K1258030.541.60-0.850.85
11K1442011.361.200.11
12K1442020.751.510.16-0.16
13K1417010.48-1.13
14K1396010.771.120.21
15K1418011.831.450.30
16K1445011.180.270.20
Block S12
1K1431011.100.370.26
2K1330010.582.010.24
3K1425011.031.500.28
4K1290010.992.300.59-0.59
5K1287010.431.140.600.55-1.940.78
7K1334010.471.631.26-1.26
8K1266011.011.060.28
9K1429011.081.370.17
10K1300010.622.220.35-0.35
11K1300020.360.09-3.483.61-0.13
12K1274011.06-0.910.17
14K1274030.88-0.700.17
15K1421010.700.500.25
16K1301011.110.690.32
Block S13
1K1434011.201.300.27
2K1295011.641.550.50
4K1260010.741.360.400.150.03-0.58
5K1403010.501.160.41-0.41
6K1587CL0.621.480.742.00-2.74
7K1403030.650.21-0.160.16
8K1420010.812.150.24
10K1385010.531.64-3.251.331.92
11K1588011.261.200.13
12K1589010.29-1.230.27
13K1446011.191.150.23
14K1292011.170.460.28
15K1353010.70-0.470.24
16K1386011.931.050.30
​
Last updated 05 December 2023 (SK)