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. 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.

In instances where participation rates meet the 70 percent criterion but fall below 85 percent, a nonresponse bias analysis is conducted to determine if the responding 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 student-weighted national school participation rates for the 2011 reading 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 and 21 districts participating in the Trial Urban District reading assessment at grades 4 and 8 met this participation rate requirement. Weighted student participation rates ranged from 89 percent to 96 percent at grade 4 and from 85 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 reading 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	7,670	93	168,200
Public	100	100	6,820	93	157,800
Private	74	70	700	95	8,000
Alabama	100	100	110	94	2,600
Alaska	100	98	130	91	2,400
Arizona	99	99	130	94	2,700
Arkansas	100	100	120	94	2,700
California	100	100	230	93	7,100
Colorado	100	97	120	92	2,600
Connecticut	100	100	110	92	2,600
Delaware	100	100	50	93	2,600
Florida	100	100	210	92	5,900
Georgia	100	100	120	94	3,900
Hawaii	100	100	80	92	2,800
Idaho	100	100	110	94	2,800
Illinois	100	100	210	94	4,100
Indiana	100	100	110	93	2,600
Iowa	100	100	130	93	2,600
Kansas	100	100	140	93	2,700
Kentucky	100	100	140	94	3,700
Louisiana	100	100	120	93	2,500
Maine	100	100	130	92	2,700
Maryland	99	99	150	92	3,300
Massachusetts	99	98	140	92	3,600
Michigan	100	100	160	93	3,800
Minnesota	100	100	140	93	2,900
Mississippi	100	100	110	92	2,500
Missouri	100	100	120	94	2,500
Montana	100	98	190	92	2,500
Nebraska	100	100	140	94	2,500
Nevada	100	97	90	93	2,700
New Hampshire	100	100	90	92	2,600
New Jersey	100	100	110	92	2,500
New Mexico	99	99	130	91	3,200
New York	99	100	170	91	4,000
North Carolina	100	100	150	92	4,200
North Dakota	100	99	190	93	2,100
Ohio	100	100	170	93	3,400
Oklahoma	100	100	150	93	2,400
Oregon	99	99	140	92	2,800
Pennsylvania	100	100	160	92	3,700
Rhode Island	100	100	50	93	2,600
South Carolina	100	100	110	94	2,600
South Dakota	100	100	230	95	2,900
Tennessee	100	100	120	92	2,600
Texas	99	100	210	94	7,200
Utah	100	100	120	92	2,800
Vermont	100	100	120	93	2,000
Virginia	100	100	110	94	2,600
Washington	100	100	140	92	3,000
West Virginia	100	100	110	92	2,700
Wisconsin	100	100	160	94	3,500
Wyoming	100	100	90	93	2,000
Other jurisdictions
BIE¹	83	85	90	90	800
District of Columbia	100	100	80	90	2,400
DoDEA²	99	95	60	92	1,600
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 Reading 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.