Designs Robust Against Presence of an Outlier in an Analysis of Covariance Model

TLDR: In this article, an attempt has been made to find robust designs in a block design set-up with covariates, when there is one single wild observation in the study variable.

Abstract: Presence of one or more aberration in the observations affects inference procedure in statistical analysis. Block designs robust against presence of aberrations can be found in the literature for both regression and block design set-ups. In this paper, an attempt has been made to find robust designs in a block design set-up with covariates, when there is one single wild observation in the study variable. Specifically, effects on the estimation of a full set of orthonormal treatment contrasts and that on the estimation of covariate parameters have been considered.