|Statistic||Item type||Block V3||Block V4||Block V5||Block V6|
|† Not applicable.
1 The "Weighted proportion of students attempting last item" is equal to 1 - (Percent not responding to last item /100).
NOTE: Item statistics in this table are described on the page Blocks of Items.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2008 Arts (Visual Arts) Assessment.
|Number of scaled items||Total||5||12||9||6|
|Dichotomously scored constructed response||0||2||1||2|
|Polytomously scored constructed response||4||6||5||2|
|Unweighted sample size||†||1,900||2,100||1,900||1,900|
|Weighted average item score||†||0.44||0.46||0.45||0.45|
|Weighted average polyserial||†||0.64||0.53||0.58||0.60|
|Weighted alpha reliability||†||0.52||0.67||0.61||0.35|
|Weighted proportion of students attempting last item1||†||0.81||0.90||0.82||0.99|