Table of Contents | Search Technical Documentation | References

NAEP Analysis and Scaling → Initial Activities → Classical Item Analysis → Block-Level Descriptive Statistics as Defined after Scaling, Grade 12 Mathematics National Assessment, by Block and School Type: 2019

​​NAEP Technical DocumentationBlock-Level Descriptive Statistics as Defined after Scaling, Grade 12 Mathematics National Assessment, by Block and School Type: 2019

Block-level descriptive statistics as defined after scaling, grade 12 mathematics DBA national assessment, by block and school type: 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. The nonpublic school sample includes only private schools, including Catholic schools. BIE and DoDEA schools are not included in either the public or nonpublic category. 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.
Number of scaled items 14 15 18 18 17 17 15 14 18 17 19
Public school
Unweighted sample size 2,200 2,200 2,300 2,300 2,200 2,200 2,400 2,300 2,400 2,400 2,300
Weighted average item score .41 .41 .48 .47 .42 .40 .39 .48 .41 .38 .44
Weighted average R biserial/polyserial .70 .66 .60 .62 .66 .60 .66 .66 .64 .68 .61
Weighted alpha reliability .82 .80 .80 .81 .79 .71 .79 .80 .82 .83 .81
Weighted proportion of students attempting last item .93 .87 .96 .94 .97 .96 .89 .96 .86 .92 .92
Nonpublic school
Unweighted sample size 200 200 200 200 200 200 200 200 200 200 200
Weighted average item score .50 .49 .54 .56 .45 .43 .50 .55 .52 .44 .51
Weighted average R biserial/polyserial .71 .68 .58 .56 .62 .55 .61 .60 .63 .62 .54
Weighted alpha reliability .83 .80 .79 .73 .74 .66 .71 .76 .79 .79 .76
Weighted proportion of students attempting last item .97 .91 .98 .97 .99 .97 .87 .96 .93 .92 .92
​

Block-level descriptive statistics as defined after scaling, grade 12 mathematics PBA national assessment, by block and school type: 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. The nonpublic school sample includes only private schools, including Catholic schools. BIE and DoDEA schools are not included in either the public or nonpublic category. 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.
Number of scaled items1414141414141313131314141413
Public school
Unweighted sample size1,7001,7001,6001,7001,7001,6001,7001,8001,8001,7001,7001,7001,7001,700
Weighted average item score.42.45.36.36.40.41.50.38.44.39.41.37.43.38
Weighted average R biserial/polyserial.64.61.65.67.64.65.62.74.68.68.63.61.65.65
Weighted alpha reliability.74.76.71.79.77.73.74.82.79.78.73.68.77.75
Weighted proportion of students attempting last item.81.94.70.88.95.93.97.82.93.92.95.96.97.90
Nonpublic school
Unweighted sample size200100100200100100200200200200200100200200
Weighted average item score.47.51.39.43.46.43.59.46.52.47.50.47.51.38
Weighted average R biserial/polyserial.63.60.56.60.64.63.57.76.71.62.53.63.64.67
Weighted alpha reliability.77.74.65.72.77.72.66.85.81.75.63.74.75.78
Weighted proportion of students attempting last item.87.98.72.91.96.941.00.89.95.96.96.991.00.95
​
Last updated 05 October 2023 (SK)