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NAEP Analysis and ScalingInitial ActivitiesClassical Item Analysis → Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Geography National Assessment, by Block: 2014
NAEP Technical Documentation

Overall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 8 Geography National Assessment, by Block: 2014

Overall descriptive statistics for item blocks as defined after scaling, grade 8 geography national assessment, by block: 2014
StatisticItem typeBlock G3Block G4Block G5Block G6Block G7Block G8Block G9
Number of scaled itemsTotal17161616141725
Multiple choice12111112101215
Dichtomously scored constructed response0010111
Polytomously scored constructed response5544349
Unweighted sample size2,3002,3002,3002,3002,3002,2002,200
Weighted average item score.49.51.51.42.56.47.54
Weighted average polyserial.56.51.51.51.61.48.53
Weighted alpha reliability.73.70.71.72.74.68.80
Weighted proportion of students attempting last item1.96.94.90.86.72.90.98
† Not applicable.
1The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item /100).
NOTE: The "weighted average item score" of polytomous items are standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items. Item statistics in this table are described on the page Blocks of Items. In 2014, grades 4 and 12 were not assessed.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2014 Geography Assessment.

Last updated 23 May 2021 (SK)