National school and student participation rates in NAEP mathematics at age 9, 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

96

97

91

92

430

95

8,600

Public

98

99

98

99

300

95

7,100

Private

72

82

69

76

140

95

1,600

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.