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.

For grade 12, the schools and students participating in NAEP assessments were selected to be representative of all schools nationally and of public schools at the state level in the eleven participating states. There are more public school students selected from the eleven participating states than the non-participating states to provide accurate estimates of the performance of students in those individual states. Proper weighting techniques were applied to ensure accurate estimates of the overall performance of students in the nation as well.

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.

Student sample sizes and target populations in NAEP reading at grade 4, by state/jurisdiction: 2009
State/jurisdiction	Sample size	Target population
Nation	189,100	3,823,000
Public	182,600	3,485,000
Private	3,000	329,000
Alabama	3,000	56,000
Alaska	2,900	9,000
Arizona	3,300	78,000
Arkansas	3,100	37,000
California	8,300	444,000
Colorado	3,000	55,000
Connecticut	3,000	41,000
Delaware	3,100	9,000
Florida	5,200	186,000
Georgia	4,400	117,000
Hawaii	3,100	13,000
Idaho	3,400	21,000
Illinois	4,600	146,000
Indiana	3,100	76,000
Iowa	3,200	34,000
Kansas	3,400	34,000
Kentucky	4,300	48,000
Louisiana	3,200	53,000
Maine	3,000	13,000
Maryland	4,000	56,000
Massachusetts	4,200	71,000
Michigan	3,900	117,000
Minnesota	3,700	62,000
Mississippi	3,100	39,000
Missouri	3,000	63,000
Montana	3,000	10,000
Nebraska	3,400	21,000
Nevada	3,400	32,000
New Hampshire	3,000	15,000
New Jersey	3,200	102,000
New Mexico	3,200	25,000
New York	4,500	194,000
North Carolina	5,000	105,000
North Dakota	2,300	7,000
Ohio	4,000	126,000
Oklahoma	3,200	46,000
Oregon	3,200	39,000
Pennsylvania	4,100	121,000
Rhode Island	2,800	10,000
South Carolina	3,300	53,000
South Dakota	3,100	9,000
Tennessee	3,300	75,000
Texas	7,100	318,000
Utah	3,700	42,000
Vermont	3,000	6,000
Virginia	3,200	86,000
Washington	3,500	75,000
West Virginia	3,100	20,000
Wisconsin	4,300	59,000
Wyoming	2,200	7,000
Other jurisdictions
BIE¹	1,200	3,000
District of Columbia	2,100	4,000
DoDEA²	2,300	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), 2009 Reading Assessment.