As with the sampling frame for the 2002 state assessment, the sampling frame for public schools consisted of the Common Core of Data (CCD) file corresponding to the 1999–2000 school year. The CCD file provided the frame for all regular public, state-operated public, Bureau of Indian Affairs, and Department of Defense Domestic Dependent Elementary and Secondary Schools (DDESS) that were open as of the 1999–2000 school year.
The frame for private schools in all three grades was developed from the 1999–2000 Private School Survey (PSS) carried out by the Census Bureau for the National Center for Education Statistics (NCES). 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 a list frame and an area frame. The list frame is a conglomeration of the 1997–98 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 more labor-intensive search for private schools in a random sample of areas throughout the United States. The areas were single counties or groups of counties sampled from an area frame containing all counties in the nation. Within each selected area a complete list of private schools was gathered using information from the Yellow Pages, religious institutions, local education agencies, Chambers of Commerce, and local government offices. Schools that were not already on the list frame were identified and added to the frame of private schools. A weight component was computed so that area frame schools represent all schools absent from the list frame, not just those in the selected areas.