|Statistics||Multiple-choice items||Dichotomous constructed-response items||Polytomous constructed-response items|
|Number of items||38||25||21|
|Average percentage missing1||8.97||11.68||16.54|
|Minimum percentage missing1||0.94||2.04||3.12|
|Maximum percentage missing1||24.74||35.98||28.45|
|Average percentage off-task2||†||0.18||0.19|
|Minimum percentage off-task2||†||0||0|
|Maximum percentage off-task2||†||0.74||0.52|
|Average weighted proportion correct||64.24||50.92||42.29|
|† Not applicable.
1 Missing includes the categories "omitted" and "not-reached."
2 "Off-task" (constructed-response items only) is a response that is unrelated to the question and considered inappropriate.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2000 Reading Assessment.