NAEP Technical DocumentationSampling Frame for the 2005 Private School National Assessment

The frame of the private schools in all three grades was developed from the 2001-02 Private School Survey (PSS), a survey conducted by the U.S. Census Bureau for the National Center for Education Statistics (NCES). The PSS is a biennial mail survey of all private schools in the 50 states and the District of Columbia. The PSS frame of schools comprises both a list frame and an area frame. The list frame is an assembly of the 1999-2000 PSS frame and more up-to-date lists from state education agencies, private school associations, and other easily accessible sources. To improve the coverage of the PSS list frame, the Census Bureau also conducted a survey to locate private schools in a random sample of geographic areas throughout the United States. The areas were single counties or groups of counties sampled from an area frame constructed from all counties in the nation. Within each selected area a complete list of private school was gathered using information from the Yellow Pages, religious institutions, local education agencies, chambers of commerce, and local government offices. Schools not already on the list frame were identified and added to the frame of private schools. A weighting component was computed by the Census Bureau so that the additional area-frame schools would represent all schools absent from the list frame, not just those in the selected area.

The sampling frame excluded all schools which were ungraded, classified as vocational with no enrollment, provided only special education, were home school entities, juvenile correctional institutions, or were parts of prisons or hospitals.

Estimated grade enrollment for private schools is the number of students in the grade as shown on the PSS, if available. If the grade specific count is not available, the estimated grade enrollment is the total school enrollment divided by the grade span.

Number of schools and enrollment in private school sampling frame, national main assessment, by grade and school type: 2005
Grade	Affiliation	Number of schools	Estimated enrollment
4	Total	23,393	449,583
	Catholic	6,631	205,794
	Lutheran	1,506	21,319
	Conservative Christian	4,576	65,729
	Other Private	8,957	122,272
	Unknown Afililiation	1,723	34,469
8	Total	20,560	409,083
	Catholic	5,955	183,122
	Lutheran	1,265	17,438
	Conservative Christian	3,916	55,373
	Other Private	7,701	118,681
	Unknown Afililiation	1,723	34,469
12	Total	11,047	321,644
	Catholic	1,312	143,185
	Lutheran	118	5,583
	Conservative Christian	3,022	36,085
	Other Private	4,872	102,322
	Unknown Afililiation	1,723	34,469
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2005.

For quality control purposes, school and student counts from the sampling frame were compared to school and student counts from previous frames (2002 and 2003). No major issues were found.

Canvassing for new private schools was restricted to contacting a sample of Roman Catholic dioceses and asking them to identify any new schools not on the list. No new schools were reported during this process.