Nonresponse Bias Analyses for the 2004 Assessment (441K PDF) were conducted for all three age categories (9, 13, and 17), since the response rates at both the school and student level were close to or less than 85 percent. At school level the weighted response rates were computed for Census Region, public/private school affiliation, school type for private schools, estimated age enrollment, and percentage of students in each race category. At student level the nonresponse rates were computed for students' race, gender, free lunch eligibility, session and assessment type, whether a student was in high or low grade for his/her age, Title 1 assistance status, and SD/LEP classification. The school counts were weighted by school base weights and enrollment, and the student counts were weighted by student base weights.
The tabulation below presents the test results of association of school and student response rates with the analysed characteristics (the test results that showed statistically significant association with response rates are presented in the tabulation).
|Age||Level||Response Rate||Characteristics with a p-value less than 0.05|
|9||School||85.73||Public/private affiliation, type pf private school, type of location, estimated age enrollment, percentage of Black students|
|Student||94.32||Free lunch eligibility, SD, ELL|
|13||School||81.45||Public/private affiliation, type of private school, estimated age enrollment, percentage of Black students|
|Student||92.20||Race, high or low grade, free lunch eligibility, Title 1, SD|
|17||School||76.96||Public/private affiliation, type of private school, percentage of Asian students|
|Student||75.18||Race, high or low grade, free lunch eligibility, SD|
|NOTE: The school response rates are based on the analyses of reading/mathematics operational session data for high grades relative to the given age.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2004.