Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

A Comparison of Four Procedures for Multiple Comparisons among Means (Pairwise Contrasts) for Arbitrary Sample Sizes

Hans K. Ury
Technometrics
Vol. 18, No. 1 (Feb., 1976), pp. 89-97
DOI: 10.2307/1267921
Stable URL: http://www.jstor.org/stable/1267921
Page Count: 9
  • Download ($14.00)
  • Cite this Item
A Comparison of Four Procedures for Multiple Comparisons among Means (Pairwise Contrasts) for Arbitrary Sample Sizes
Preview not available

Abstract

For the situation in which the contrasts of interest are limited to the $\left( \matrix K \\ 2 \endmatrix \right)$ pairwise comparisons among the means of K samples of equal or unequal sizes, four normal univariate single-stage multiple comparison procedures are compared for significance levels not exceeding 0.05: Scheffé's S-method, Dunn's (1, 2] and Šidák's [17] improved version of the Bonferroni method, Hochberg's GT2 procedure [8] utilizing the maximum modulus, and Spjøtvoll and Stoline's T′-method [19]. Rules are given for determining if any method is uniformly preferable (best for all $\left( \matrix K \\ 2 \endmatrix \right)$ contrasts). Nonuniform preference rules are also proposed and applied to some examples. Auxiliary tables are provided for selecting a method for significance levels 0.01 and 0.05 for several values of ν, the number of degrees of freedom of an independent variance estimate, and K. It is shown that the T′-method is uniformly preferable when the sample sizes are "nearly" equal, while one of the other methods will be uniformly preferable when all sample sizes are "sufficiently" different. The comparison is readily extended to the case in which only a subset of the $\left( \matrix K \\ 2 \endmatrix \right)$ pairwise contrasts is of interest.

Page Thumbnails

  • Thumbnail: Page 
89
    89
  • Thumbnail: Page 
90
    90
  • Thumbnail: Page 
91
    91
  • Thumbnail: Page 
92
    92
  • Thumbnail: Page 
93
    93
  • Thumbnail: Page 
94
    94
  • Thumbnail: Page 
95
    95
  • Thumbnail: Page 
96
    96
  • Thumbnail: Page 
97
    97