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NAEP Technical DocumentationBlock and Scale Composition, Grade 8 Science National Assessment: 2019
Block composition before scaling, grade 8 science DBA national assessment, by item type and block: 2019
Block
Total number of items
Number of multiple-choice items
Number of constructed-response items
2-category
3-category
4-category
5-category
DBA = Digitally based assessment. For a small number of constructed-response items, adjacent categories were combined.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
Total
212
134
9
40
18
11
S2
17
10
3
2
2
0
S3
17
12
0
1
2
2
S4
18
13
0
2
1
2
S5
18
13
0
2
2
1
S6
17
11
0
4
1
1
S7
18
11
3
3
0
1
S8
18
13
1
1
2
1
S9
18
13
0
4
1
0
S10
18
14
0
2
1
1
S11
17
12
0
4
1
0
S12
15
9
0
4
1
1
H1
4
0
0
1
2
1
I1
11
2
2
6
1
0
I4
6
1
0
4
1
0
Block composition before scaling, grade 8 science PBA national assessment, by item type and block: 2019
Block
Total number of items
Number of multiple-choice items
Number of constructed-response items
2-category
3-category
4-category
5-category
PBA = Paper-based assessment. For a small number of constructed-response items, adjacent categories were combined.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
Total
166
115
1
21
18
11
S3
17
12
0
1
2
2
S4
18
13
0
2
1
2
S5
18
13
0
2
2
1
S6
17
11
0
4
1
1
S7
16
10
0
1
2
3
S8
18
13
1
1
2
1
S9
14
8
0
1
5
0
S10
17
14
0
2
1
0
S11
16
12
0
3
1
0
S12
15
9
0
4
1
1
Scale composition for new blocks as defined after univariate scaling, grade 8 science DBA national assessment, by item type and scale: 2019
Scale
Multiple-choice items
Dichotomously scored constructed-response items
Polytomously scored constructed-response items
Scaled
Dropped
Scaled
Dropped
Polytomous (uncollapsed)
Dichotomous collapsed
Polytomous collapsed
Dropped
DBA = Digitally based assessment. "Dropped" denotes items that were deleted from the final scaling. "Collapsed" denotes items that had categories that were combined and recoded for scaling. Polytomous items may be collapsed if they show IRT misfit and adjacent categories need to be combined to achieve better IRT model fit. Some items were administered previously under different contexts. All DBA items are included in the counts because 2019 was the first year of DBA administration for NAEP science.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
Univariate
127
4
9
0
46
13
11
0
Scale composition for new blocks as defined after multivariate scaling, grade 8 science DBA national assessment, by item type and subscale: 2019
Subscale
Multiple-choice items
Dichotomously scored constructed-response items
Polytomously scored constructed-response items
Scaled
Dropped
Scaled
Dropped
Polytomous (uncollapsed)
Dichotomous collapsed
Polytomous collapsed
Dropped
DBA = Digitally based assessment. "Dropped" denotes items that were deleted from the final scaling. "Collapsed" denotes items that had categories that were combined and recoded for scaling. Polytomous items may be collapsed if they show IRT misfit and adjacent categories need to be combined to achieve better IRT model fit. Some items were administered previously under different contexts. All DBA items are included in the counts because 2019 was the first year of DBA administration for NAEP science.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
Total
129
2
9
0
59
6
5
0
Physical science
40
1
5
0
15
1
3
0
Earth and space sciences
52
0
4
0
22
5
2
0
Life science
37
1
0
0
22
0
0
0
Scale composition for trend blocks as defined after univariate scaling, grade 8 science PBA national assessment, by item type and scale: 2019
Scale
Multiple-choice items
Dichotomously scored constructed-response items
Polytomously scored constructed-response items
Concurrent
Split
Dropped
Concurrent
Split
Dropped
Polytomous (uncollapsed)
Dichotomous collapsed
Polytomous collapsed
Split
Dropped
PBA = Paper-based assessment. "Concurrent" and “uncollapsed” denote items that were scaled as the same items across assessment years. "Split" denotes items that were scaled as different items in each assessment year. Items may be split if they display cross-year drift and need to be treated as separate items. "Dropped" denotes items that were deleted from the final scaling. "Collapsed" denotes items that had categories that were combined and recoded for scaling. Polytomous items may be collapsed if they show IRT misfit and adjacent categories need to be combined to achieve better IRT model fit. For multiple-choice and dichotomously scored constructed-response items, the total number of items is the sum of the three categories: concurrent, split, and dropped. The number of concurrent polytomously scored constructed-response items is equal to the total number in the first three categories under "Polytomously scored constructed-response items."
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
Univariate
104
8
3
0
1
0
38
6
6
6
0
Scale composition for trend blocks as defined after multivariate scaling, grade 8 science PBA national assessment, by item type and subscale: 2019
Subscale
Multiple-choice items
Dichotomously scored constructed-response items
Polytomously scored constructed-response items
Concurrent
Split
Dropped
Concurrent
Split
Dropped
Polytomous (uncollapsed)
Dichotomous collapsed
Polytomous collapsed
Split
Dropped
PBA = Paper-based assessment. "Concurrent" and “uncollapsed” denote items that were scaled as the same items across assessment years. "Split" denotes items that were scaled as different items in each assessment year. Items may be split if they display cross-year drift and need to be treated as separate items. "Dropped" denotes items that were deleted from the final scaling. "Collapsed" denotes items that had categories that were combined and recoded for scaling. Polytomous items may be collapsed if they show IRT misfit and adjacent categories need to be combined to achieve better IRT model fit. For multiple-choice and dichotomously scored constructed-response items, the total number of items is the sum of the three categories: concurrent, split, and dropped. The number of concurrent polytomously scored constructed-response items is equal to the total number in the first three categories under "Polytomously scored constructed-response items."
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Science Assessment.
