National School Lunch Program: Established by President Truman in 1946, the program is a federally-assisted meal program operated in public and private nonprofit schools and residential child care centers. To be eligible for reduced-price lunch, a student must be from a household with an income at 185 percent of the poverty level. To be eligible for free lunch, the household income must be at 130 percent of the poverty level. See also supplemental note 1.

National Target Population: In cases where it was not possible to assess the entire International Target Population on the 2007 Trends in International Mathematics and Science Study (TIMSS), countries were permitted to define a National Target Population that excluded part of the International Target Population. Exclusions are clearly annotated in NCES 2009-001. See also National Target Population and supplemental note 5.

Nonresident alien: A person who is not a citizen of the United States, who is in this country on a temporary basis, and who does not have the right to remain indefinitely.

Nursery school: A separately organized and administered elementary school for groups of children during the year or years preceding kindergarten, which provides educational experiences under the direction of professionally qualified teachers. See also Preschool.