About the Assessment: Participation Rates

National participation

To ensure unbiased samples, NAEP requires that participation rates for original school samples be 70 percent or higher to report national results separately for public and private schools. In instances where participation rates meet the 70 percent criteria but fall below 85 percent, a nonresponse bias analysis is conducted to determine if the responding school sample is not representative of the population, thereby introducing the potential for nonresponse bias.

Before substituting new schools for originally sampled schools that declined to participate, the weighted national school participation rates for the 2009 mathematics assessment were 97 percent for grade 4 (100 percent for public schools and 73 percent for private schools), 97 percent for grade 8 (100 percent for public schools and 72 percent for private schools), and 83 percent for grade 12 (86 percent for public and 52 percent for private). Weighted student participation rates were 95 percent at grade 4, 93 percent at grade 8, and 80 percent at grade 12. The nonresponse bias analysis for private schools at grades 4 and 8 showed that substitution and weight adjustments reduced the potential bias.  At grade 12, the school participation rate for private schools fell below the standard for reporting.

Because the grade 12 weighted student participation rate in public schools was below 85 percent (79 percent), a student nonresponse bias analysis was conducted. That analysis showed that the responding student sample differed from the original student sample with respect to race, relative age, and student disability status. After adjusting the sampling weights to account for student nonresponse, the remaining bias was small, with the nonresponse adjusted estimates for the three identified variables differing from the unadjusted estimates by plus or minus 0.1 percentage points.

State and district participation

Standards established by the National Assessment Governing Board require that school participation rates for the original state samples need to be at least 85 percent for results to be reported. In 2009, all 52 states and jurisdictions, along with all 18 districts participating in the mathematics assessment at grades 4 and 8 met this participation rate requirement. Because the weighted school participation rate in Illinois was 84.5 percent, a school nonresponse bias analysis was conducted for the grade 12 public school sample in that state. That analysis showed that the potential nonresponse bias was effectively reduced by including substitute schools and adjusting the sampling weights to account for school nonresponse. The school participation rates for the remaining 10 states all met the required standard with weighted participation rates ranging from 92 to 100 percent.

Student nonresponse bias analyses were conducted at grade 12 for Connecticut, Florida, Illinois, Iowa, Massachusetts, New Hampshire, New Jersey, South Dakota, and West Virginia, where the student response rate fell below 85 percent. Across these nine states, after nonresponse adjustments, the percentage difference between nonresponse adjusted sample and eligible student sample was 1.3 percent or less. Based on the student characteristics available, there does not appear to be evidence of substantial bias resulting from student nonresponse.

The tables below provide participation rates before substitution.

Learn more about the sampling design.

School participation Student participation State/jurisdiction Student- School- weighted weighted percent percent 97 87 7,030 93 161,700 100 100 6,520 92 156,200 72 68 360 95 3,100 100 100 110 94 2,700 98 88 100 90 2,400 100 100 130 93 2,900 100 100 120 92 2,600 100 100 230 92 7,100 100 100 120 93 2,700 100 100 110 91 2,800 100 100 50 91 2,700 100 100 160 91 4,300 100 100 120 93 3,500 100 100 70 92 2,800 100 100 110 94 3,000 100 100 200 94 4,100 100 100 110 93 2,600 100 100 130 94 2,600 99 99 120 93 2,700 100 100 130 94 3,700 100 100 120 92 2,600 100 100 130 92 2,700 100 100 130 92 3,200 100 100 140 92 3,600 100 100 150 93 3,400 100 100 140 92 2,900 100 100 120 94 2,800 100 100 130 93 2,700 100 98 170 91 2,600 100 100 120 95 2,700 100 100 90 91 2,800 96 96 90 89 2,500 100 100 110 93 2,800 100 100 110 90 2,500 97 98 150 90 3,800 100 100 150 93 4,400 100 100 180 95 2,200 100 100 190 93 3,500 100 100 150 93 2,600 100 100 130 93 2,900 100 100 150 92 3,600 100 100 60 92 2,700 100 100 110 94 2,800 100 100 220 95 2,800 100 100 120 94 2,900 99 100 170 92 5,800 100 100 110 91 2,900 100 100 120 92 2,800 100 100 110 93 2,800 100 100 130 92 2,800 100 100 120 93 2,900 99 99 170 93 3,500 100 100 80 91 1,900 80 83 60 90 800 100 100 90 87 1,700 99 97 60 92 1,600 1 Bureau of Indian Education. 1 Department of Defense Education Activity (overseas and domestic schools). NOTE: The number of schools is rounded to the nearest ten. The number of students is rounded to the nearest hundred. The national totals for schools include Department of Defense Education Activity (overseas and domestic schools) and Bureau of Indian Education schools, which are not included in either the public or private totals. The national totals for students include students in these schools. Columns of percentages have different denominators. Detail may not sum to totals because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 Mathematics Assessment.