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NAEP Analysis and Scaling → Drawing Inferences from NAEP Results → Comparison of Multiple Groups

Comparison of Multiple Groups

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Bonferroni Procedure

False Discovery Rate Procedure

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To assure that comparisons that are made using NAEP data are as accurate as possible, error rates are controlled when multiple comparisons are made. When making a number of comparisons in a single analysis, such as analyzing White student performance versus the performance of Black, Hispanic, Asian/Pacific Islander, and American Indian students, the probability of finding significance by chance for at least one comparison increases with the family size or number of comparisons. There are several ways to take into account how many related comparisons are being made. NAEP used only the Bonferroni procedure prior to the 1996 assessment. Starting with the 1998 assessment, NAEP has used only the Benjamini-Hochberg false discovery rate (FDR) procedure.

Last updated 10 June 2008 (TS)

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