NAEP Technical DocumentationFourth-, Eighth-, and Twelfth-Grade Schools and Enrollment in the 2007 Private School Sampling Frame

The following table displays, by grade and affiliation, the number of private schools in the sampling frame and their estimated enrollment. For grades 4 and 8, enrollment was estimated for each school as the Private School Universe Survey (PSS)-reported enrollment averaged across grades 1 through 8. For grade 12, the average was computed over grades 9 through 12.

The counts presented below are of respondents to the PSS. In addition, there were 1,747 nonrespondents to PSS for which grade span, affiliation, and enrollment were unknown. To maintain the best possible coverage of the population of private schools, a small sample of PSS nonrespondents was selected at each of the three targeted grades.

Number of schools and enrollment in private school sampling frame, national assessment, by school affiliation and grade: 2007
Grade	Affiliation	Number of schools	Estimated enrollment
4	Total	19,537	370,095
	Catholic	6,240	183,830
	Non-Catholic	13,297	186,265
8	Total	16,984	355,938
	Catholic	5,619	176,461
	Non-Catholic	11,365	179,477
12	Total	8,167	275,802
	Catholic	1,234	140,274
	Non-Catholic	6,933	135,528
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2007.