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NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 12 Mathematics National Assessment, by Block: 2019

​​NAEP Technical DocumentationOverall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 12 Mathematics National Assessment, by Block: 2019

Overall descriptive statistics for item blocks as defined after scaling, grade 12 mathematics DBA national assessment, by block: 2019
Statistic Block M1 Block M2 Block M3 Block M4 Block M5 Block M6 Block M7 Block M8 Block M9 Block M10 Block M11
The "Weighted average item score" of polytomous items is standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items.
The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item / 100). Weights are applied to reflect sampling design.
DBA = Digitally based assessment. CR = Constructed response. Item statistics in this table are described on the page Blocks of Items.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Mathematics Assessment.
Total number of scaled items 14 15 18 18 17 17 15 14 18 17 19
Number of multiple-choice items 4 6 12 13 12 12 7 7 13 12 14
Number of dichotomously scored CR items 5 3 2 1 3 2 5 3 1 1 3
Number of polytomously scored CR items 5 6 4 4 2 3 3 4 4 4 2
Unweighted sample size 2,300 2,300 2,400 2,300 2,300 2,300 2,500 2,400 2,500 2,500 2,400
Weighted average item score .41 .41 .48 .47 .42 .40 .40 .49 .42 .39 .44
Weighted average R biserial/polyserial .71 .66 .59 .62 .66 .59 .66 .65 .64 .68 .61
Weighted alpha reliability .82 .80 .80 .81 .79 .71 .79 .80 .82 .82 .81
Weighted proportion of students attempting last item .94 .87 .96 .94 .97 .96 .89 .96 .86 .92 .92
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Overall descriptive statistics for item blocks as defined after scaling, grade 12 mathematics PBA national assessment, by block: 2019
StatisticBlock M1Block M2Block M3Block M4Block M5Block M6Block M7Block M8Block M9Block M10Block M11Block M12Block M13Block M14
The "Weighted average item score" of polytomous items is standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items.
The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item / 100). Weights are applied to reflect sampling design.
PBA = Paper-based assessment. CR = Constructed response. Item statistics in this table are described on the page Blocks of Items.
U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2019 Mathematics Assessment.
Total number of scaled items1414141414141313131314141413
Number of multiple-choice items9109810101081089101010
Number of dichotomously scored CR items10211111103221
Number of polytomously scored CR items44353324252222
Unweighted sample size1,7001,7001,7001,7001,7001,7001,8001,8001,9001,8001,7001,7001,7001,800
Weighted average item score.42.45.37.37.41.42.51.39.45.40.42.38.44.38
Weighted average R biserial/polyserial.64.61.65.67.64.65.62.74.69.67.62.61.65.65
Weighted alpha reliability.74.76.71.79.77.73.74.83.79.78.72.69.77.75
Weighted proportion of students attempting last item.81.95.70.88.95.93.98.83.93.92.95.96.97.90
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Last updated 05 October 2023 (SK)