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 4, 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	97	92	8,540	95	213,100
Public	100	100	7,760	95	202,900
Private	74	68	560	95	6,100
Alabama	99	100	110	95	3,000
Alaska	100	100	180	93	2,800
Arizona	99	99	120	94	3,800
Arkansas	100	100	120	95	3,600
California	100	100	280	95	9,300
Colorado	100	100	120	93	3,600
Connecticut	100	100	110	94	3,200
Delaware	100	100	100	95	3,400
Florida	100	100	220	95	7,300
Georgia	100	100	170	94	5,300
Hawaii	100	100	120	93	3,500
Idaho	100	100	130	95	3,700
Illinois	100	100	190	94	5,200
Indiana	100	100	110	95	3,600
Iowa	100	100	140	96	3,500
Kansas	99	99	140	95	3,200
Kentucky	100	100	150	94	4,700
Louisiana	100	100	120	94	3,400
Maine	100	100	160	94	3,300
Maryland	100	100	170	94	4,300
Massachusetts	100	100	180	94	5,000
Michigan	100	100	150	94	4,100
Minnesota	100	100	140	94	3,700
Mississippi	100	100	110	94	3,000
Missouri	100	100	130	95	3,600
Montana	100	100	190	94	3,200
Nebraska	100	100	160	95	3,100
Nevada	100	100	120	96	4,000
New Hampshire	100	100	130	94	3,300
New Jersey	99	99	110	95	3,100
New Mexico	100	100	150	93	4,100
New York	100	100	160	94	4,800
North Carolina	100	100	170	94	5,400
North Dakota	100	100	250	96	3,000
Ohio	100	100	180	94	4,200
Oklahoma	100	100	140	95	3,100
Oregon	99	99	140	95	3,700
Pennsylvania	100	100	160	94	4,700
Rhode Island	100	100	110	95	3,300
South Carolina	100	100	110	94	3,400
South Dakota	100	100	190	96	3,300
Tennessee	100	100	120	95	3,400
Texas	99	99	300	95	8,900
Utah	100	100	120	94	4,000
Vermont	100	100	220	94	2,700
Virginia	100	100	110	95	3,800
Washington	100	100	130	95	4,000
West Virginia	100	100	150	95	3,100
Wisconsin	100	100	180	95	4,600
Wyoming	100	100	180	95	3,000
Other jurisdictions
BIE¹	83	85	110	91	1,000
District of Columbia	100	100	120	95	2,200
DoDEA²	99	97	110	94	3,100
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. For each jurisdiction, the percentile denominator is the number of schools or students for that jurisdiction. 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.