About the Assessment: Target Population and Sample Size

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. The results from the assessed students are combined to provide accurate estimates of the overall performance of students in the nation and in individual states and other jurisdictions.

While national results reflect the performance of students in both public schools and nonpublic schools (i.e., private schools, Bureau of Indian Education schools, and Department of Defense schools), state-level results reflect the performance of public school students only. Results are also reported separately for Department of Defense schools in state tables and maps. More information on sampling can be found in NAEP Technical Documentation.

The sample of students in the participating Trial Urban District Assessment (TUDA) school districts is an extension of the sample of students who would usually be selected by NAEP as part of state and national samples. Results for students in the TUDA samples are also included in state and national samples with appropriate weighting.

Some charter schools that operate within the geographic boundaries of a school district are independent of the district and are not included in the districts' Adequate Yearly Progress (AYP) report to the U.S. Department of Education under the Elementary and Secondary Education Act. Beginning in 2009, charter schools of this type are no longer included in the results for TUDA districts as they had been in past NAEP assessments.

School districts vary in whether the charter schools within their boundaries are independent of the districts. Prior to 2009, charter schools were included in the TUDA district results if they were listed as part of the district’s Local Education Agency in the NCES Common Core of Data. Beginning in 2009, charter schools were included in TUDA district results if they contributed to the district’s AYP results as part of the Elementary and Secondary Education Act.

Student sample sizes and target populations in NAEP reading at grade 4, by state/jurisdiction: 2011
State/jurisdiction	Sample size	Target population
Nation	222,200	3,940,000
Public	211,700	3,614,000
Private	6,200	317,000
Alabama	3,100	54,000
Alaska	2,900	9,000
Arizona	3,900	80,000
Arkansas	3,700	37,000
California	9,600	438,000
Colorado	3,600	61,000
Connecticut	3,200	41,000
Delaware	3,700	10,000
Florida	7,500	195,000
Georgia	5,600	129,000
Hawaii	3,500	13,000
Idaho	3,800	21,000
Illinois	5,300	157,000
Indiana	3,600	80,000
Iowa	3,500	36,000
Kansas	3,300	35,000
Kentucky	5,200	51,000
Louisiana	3,400	56,000
Maine	3,300	14,000
Maryland	4,900	60,000
Massachusetts	5,400	76,000
Michigan	4,300	113,000
Minnesota	3,800	62,000
Mississippi	3,100	35,000
Missouri	3,700	68,000
Montana	3,300	11,000
Nebraska	3,300	22,000
Nevada	4,100	34,000
New Hampshire	3,400	14,000
New Jersey	3,500	99,000
New Mexico	4,400	25,000
New York	4,900	197,000
North Carolina	5,500	112,000
North Dakota	3,200	7,000
Ohio	4,500	125,000
Oklahoma	3,300	45,000
Oregon	3,900	45,000
Pennsylvania	4,900	130,000
Rhode Island	3,400	11,000
South Carolina	3,500	52,000
South Dakota	3,400	9,000
Tennessee	3,700	75,000
Texas	10,400	359,000
Utah	4,200	43,000
Vermont	2,800	6,000
Virginia	3,900	96,000
Washington	4,100	77,000
West Virginia	3,200	20,000
Wisconsin	4,700	62,000
Wyoming	3,000	7,000
Other jurisdictions
BIE¹	1,100	3,000
District of Columbia	2,200	5,000
DoDEA²	3,300	7,000
¹ Bureau of Indian Education. ² Department of Defense Education Activity (overseas and domestic schools). NOTE: The sample size is rounded to the nearest hundred. The target population is rounded to the nearest thousand. Data for BIE and DoDEA schools are counted in the overall nation total, but not in the nation (public) total. Data for the District of Columbia public schools are counted, along with the states, in nation (public). 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.