NAEP Technical DocumentationSummary Response Rates for the NAEP 2008 Reading Long-Term Trend Assessment

Summary item response rates, by item type and age, reading LTT assessment: 2008
Age	Statistic	Multiple-choice items	Dichotomous constructed-response items	Polytomous constructed-response items
† Not applicable. ¹ Missing responses includes the categories "omitted" and "not-reached." ² An "off-task" response (constructed-response items only) is a response that is unrelated to the question and is considered inappropriate. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2008 Reading Long-term Trend Assessment.
9	Number of items	84.00	†	4.00
	Average percent missing¹	2.87	†	6.15
	Minimum	0.37	†	3.70
	Maximum	14.41	†	9.71
	Average percent off-task²	†	†	1.17
	Minimum	†	†	0.72
	Maximum	†	†	1.60
	Average weighted proportion correct	65.40	†	36.21
13	Number of items	100.00	†	7.00
	Average percent missing¹	2.42	†	3.53
	Minimum	0.09	†	1.90
	Maximum	11.62	†	5.52
	Average percent off-task²	†	†	0.29
	Minimum	†	†	0.09
	Maximum	†	†	0.50
	Average weighted proportion correct	75.48	†	53.55
17	Number of items	96.00	†	8.00
	Average percent missing¹	2.19	†	6.08
	Minimum	0.32	†	3.34
	Maximum	14.62	†	13.32
	Average percent off-task²	†	†	0.60
	Minimum	†	†	0.14
	Maximum	†	†	1.09
	Average weighted proportion correct	78.26	†	56.10

Last updated 27 October 2011 (GF)