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Final Primary Sampling Unit (PSU) Sample

A primary sampling unit (PSU) sample was drawn independently from each of the 76 noncertainty strata defined in Final Primary Sampling Unit Strata. One PSU was selected with probability proportionate to size (with size equal to number of youths) within each stratum. Also, 29 PSUs were included in the sample of PSUs with certainty.

Distribution of sampled PSUs by primary sampling unit (PSU) type: 2006
PSU type Number of
sampled PSUs
Total 105
Metropolitan status
Metropolitan 83
Non-metropolitan 22
Census region
Northeast 15
Midwest 23
South 42
West 25

Certainty/metropolitan status

Certainty metropolitan 29
Noncertainty metropolitan 54
Noncertainty non-metropolitan 22
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2006 .

Last updated 13 January 2010 (JL)

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