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NAEP Sample Design → NAEP 2005 Sample Design → National Assessment Sample Design → Private School National Assessment

Private School National Assessment

       

Target Population

Sampling Frame

Stratification of Schools

School Sample Selection

Substitute Schools

Ineligible Schools

Student Sample Selection

Participation

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The private school sample (the "delta sample") was designed to produce a nationally representative school and student sample for all of the studies (operational, bridge, and pilot) among the students in private schools in the United States.

For each grade, private schools were divided into four strata based on school affiliation, and implicitly stratified within the four explicit strata. The table below shows target sample sizes for the student assessments for each assessment type (operational, science bridge, pilot), by private school stratum (Catholic, Lutheran, Conservative Christian, and other private), and overall, for fourth, eighth, and twelfth grades, respectively.

The design called for oversampling of specific private school groups for those assessments where state participation is required - namely grade 4 and grade 8 reading and mathematics. Consequently the private school samples for those assessments are much larger than for science and for grade 12.

Target sample sizes were adjusted for expected school and student response and eligibility.

 

Target student sample for private schools, by stratum, grade, and assessment: 2005
Sample Total Catholic Lutheran Conservative
Christian
Other
Private
Total fourth grade 16,040 8,025 1,693 2,107 4,215
Mathematics 6,000 3,000 750 750 1,500
Reading 6,000 3,000 750 750 1,500
Science 2,400 1,200 120 360 720
Science bridge 1,200 600 60 180 360
Pilot 440 225 13 67 135
Total eighth grade 16,090 8,050 1,696 2,114 4,230
Mathematics 6,000 3,000 750 750 1,500
Reading 6,000 3,000 750 750 1,500
Science 2,400 1,200 120 360 720
Science bridge 1,200 600 60 180 360
Pilot 490 250 16 74 150
Total twelfth grade 9,550 4,775 477 1,433 2,865
Mathematics 2,000 1,000 100 300 600
Reading 2,600 1,300 130 390 780
Science 2,900 1,450 145 435 870
Science bridge 1,200 600 60 180 360
Pilot 850 425 42 128 255
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2005.

Samples were based on a two-stage design that involved selection of schools within strata and selection of students within schools. The first-stage samples of schools were selected with probability proportional to a measure of size based on the estimated grade-specific enrollment in the schools.


Last updated 30 July 2009 (EH)

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National Center for Education Statistics - http://nces.ed.gov
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