About the Assessment: Participation Rates

The schools and students participating in NAEP assessments are selected to be representative of all schools nationally and of public schools at the state level. Samples of schools and students are drawn from each state and from the District of Columbia and Department of Defense schools. Because each school that participated in the assessment, and each student assessed, represents a portion of the population of interest, the results are weighted to account for the disproportionate representation of the selected sample. This includes oversampling of schools with high concentrations of students from certain racial/ethnic groups and the lower sampling rates of students who attend very small schools. Read more technical information about weighting adjustments made at the school and student level.

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. Nonresponse bias analyses were conducted for the private school samples at both grades.

The results of the nonresponse bias analyses showed that, while the original responding school samples may not have been fully representative, including substitute schools and adjusting the sampling weights to account for school nonresponse were at least partially effective in reducing the potential for nonresponse bias. However, some variables examined in the analysis still indicated potential bias after nonresponse adjustments. For instance, smaller schools were somewhat overrepresented in the final private school samples at both grades, and the responding sample of private schools at grade 8 contained a higher percentage of Black students and a lower percentage of White students than the original sample of eligible private schools.

Before substituting new schools for originally sampled schools that declined to participate, the weighted national school participation rates for the 2011 mathematics assessment were 97 percent for grade 4 (100 percent for public schools and 74 percent for private schools), and 98 percent for grade 8 (100 percent for public schools and 74 percent for private schools). Weighted student participation rates were 95 percent at grade 4 and 93 percent at grade 8.

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 2011, all 52 states and jurisdictions, along with all 21 districts participating in the Trial Urban District mathematics assessment at grades 4 and 8 met this participation rate requirement. Weighted student participation rates for TUDA ranged from 89 percent to 97 percent at grade 4 and from 84 percent to 96 percent at grade 8.

The tables below provide participation rates before substitution.

Learn more about the sampling design.

School and student participation rates in NAEP mathematics at grade 8, by state/jurisdiction: 2011
State/jurisdiction	Student- weighted percent	School- weighted percent	Number of schools participating	Student- weighted percent	Number of students assessed
	School participation			Student participation
Nation	98	88	7,610	93	175,200
Public	100	100	6,760	93	164,400
Private	74	70	690	95	8,300
Alabama	100	100	110	94	2,800
Alaska	100	98	120	89	2,400
Arizona	99	99	130	93	2,800
Arkansas	100	100	120	93	2,800
California	100	100	230	92	7,300
Colorado	100	97	120	93	2,800
Connecticut	100	100	110	93	2,800
Delaware	100	100	50	93	2,800
Florida	100	100	210	93	6,200
Georgia	100	100	120	93	4,100
Hawaii	100	100	80	92	2,900
Idaho	100	100	110	94	3,000
Illinois	100	100	210	93	4,200
Indiana	100	100	110	93	2,700
Iowa	100	100	130	93	2,700
Kansas	100	100	140	93	2,800
Kentucky	100	100	140	93	3,900
Louisiana	100	100	120	93	2,600
Maine	100	100	130	92	2,700
Maryland	99	99	150	92	3,500
Massachusetts	99	98	140	92	3,800
Michigan	100	100	160	93	4,000
Minnesota	100	100	140	93	3,000
Mississippi	100	100	110	94	2,700
Missouri	100	100	120	94	2,600
Montana	100	98	180	90	2,600
Nebraska	100	100	140	93	2,600
Nevada	100	97	90	94	2,800
New Hampshire	100	100	90	91	2,700
New Jersey	100	100	110	92	2,600
New Mexico	99	99	120	91	3,400
New York	99	100	170	91	4,200
North Carolina	100	100	150	92	4,400
North Dakota	100	99	180	95	2,300
Ohio	100	100	170	93	3,500
Oklahoma	100	100	150	92	2,400
Oregon	99	99	140	93	2,900
Pennsylvania	100	100	160	92	3,800
Rhode Island	100	100	50	92	2,700
South Carolina	100	100	110	94	2,700
South Dakota	100	100	220	94	3,100
Tennessee	100	100	120	91	2,800
Texas	99	100	210	94	7,500
Utah	100	100	110	91	2,900
Vermont	100	100	120	94	2,100
Virginia	100	100	110	93	2,700
Washington	100	100	140	92	3,200
West Virginia	100	100	110	93	2,800
Wisconsin	100	100	160	93	3,600
Wyoming	100	100	90	92	2,100
Other jurisdictions
BIE¹	83	85	90	91	900
District of Columbia	100	100	80	90	2,400
DoDEA²	99	95	60	95	1,700
¹ Bureau of Indian Education. ² 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), 2011 Mathematics Assessment.

The student-weighted school participation rates are calculated based on the estimated number of students represented by either the initially selected schools that participated in the assessment (before substitution) or the participating schools, whether originally selected or selected as a substitute for a school that chose not to participate (after substitution). The school-weighted school participation rates are calculated based on the estimated number of schools either before or after substitutions.