Sankhya: The Indian Journal of Statistics
2001, Volume 63, Series B, Pt. 3, pp. 338--350
A USEFUL STATISTIC FOR STUDYING OUTLIERS IN EXPERIMENTAL DESIGNS
LALMOHAN BHAR and V.K.GUPTA, Indian Agricultural Statistics Research Institute, New Delhi
SUMMARY. For testing outliers in the linear model (y, X(theta), (sigma)²I) for experimental designs, the Cook-statistic (Cook, 1977) is appropriately modified. Special emphasis is given to the case of a single outlier in block designs. This newly developed statistic is applied to a data set obtained from a randomized complete block design. A new cirterion for robustness of experimental designs against the presence of a single outlier is proposed. This new criterion is based on average Cook-statistic. A number of designs for one-way elimination of heterogeneity are identified that are robust against the presence of a single outlier.
AMS subject classification. 62K10.
Key words and phrases. Outlier, linear model, Cook-statistic, robustness.
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