NAEP Technical DocumentationSubstitute Public Schools for the 2008 Arts Assessment

To the extent possible, substitutes were preselected for the public school samples by sorting the school frame file according to the actual order used in the sampling process (the implicit stratification). For operational reasons, the original selection order was imbedded within the sampled primary sampling unit (PSU) and state. Each sampled school had each of its nearest neighbors within the same sampling stratum on the school frame file identified as a potential substitute. When grade enrollment was used as the last sort ordering variable the nearest neighbors had grade enrollment values very close to that of the sampled school. This was done in order to facilitate the selection of about the same number of students within the substitute as would have been selected from the original sampled school.

Schools were disqualified as potential substitutes if they were already selected in the original arts public school sample or assigned as a substitute for another eighth-grade public school (earlier in the sort ordering). In addition, public schools were disqualified as potential substitutes if they were already selected in the original long-term trend (LTT) sample for any age (9, 13, or 17), field test, or science interactive computer testing, or already assigned as an LTT substitute school.

If both nearest neighbors were still eligible to be substitutes, the one with a closer grade enrollment was chosen. If both nearest neighbors were equally distant from the sampled school in their grade enrollment (an uncommon occurrence), one of the two was randomly selected.

Of the approximately 230 originally sampled public schools, all but about 10 were not assigned a substitute. However, less than five substitute public schools participated in the arts assessment.

Last updated 12 January 2011 (JL)

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