National school and student participation rates in NAEP mathematics at age 13, by type of school: 2008

School participation

Student participation

Student-weighted

School-weighted

Number of schools participating after substitution

Student-weighted percent

Number of students assessed

Type of school

Percent before substitution

Percent
after
substitution

Percent before substitution

Percent
after
substitution

Nation

95

97

89

92

420

94

8,500

Public

97

98

97

98

300

93

7,000

Private

79

82

73

79

120

95

1,500

NOTE: Columns of percentages have different denominators. The student-weighted school participation rates are calculated based on the estimated number of students represented by either the initially selected schools that participated in the assessment (before substitution) or the participating schools whether originally selected or selected as a substitute for a school that chose not to participate (after substitution). The school-weighted school participation rates are calculated based on the estimated number of schools either before or after substitution. The numbers of schools are rounded to the nearest ten, and the numbers of students are rounded to the nearest hundred. 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), 2008 Long-Term Trend Mathematics Assessment.