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On the effect of correlation and unequal variances in detecting a spurious observation
Author(s) -
Young Dean M.,
Pavur Robert,
Marco Virgil R.
Publication year - 1989
Publication title -
canadian journal of statistics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.804
H-Index - 51
eISSN - 1708-945X
pISSN - 0319-5724
DOI - 10.2307/3314767
Subject(s) - mathematics , covariance , outlier , statistics , univariate , spurious relationship , combinatorics , humanities , multivariate statistics , philosophy
Srivastava (1980) has shown that Grubbs's (1950) test for a univariate outlier is robust against the effect of equicorrelation. In this note we extend Srivastava's result by giving a more general covariance structure, which relaxes both the covariance structure and the assumption of equal variances. We also show that under the more general covariance structure, the power of Grubbs's test, as well as the significance level, is identical to the independently and identically distributed case.