Yuli Liang: Local influence analysis in cross-over designs

The aim of this work is to develop a new methodology to detect influential observations in cross-over design models with random individual effects. Various case-weight perturbations are performed. We derived the exact solution of influence of the perturbations on each parameter estimate and its dispersion matrix. Closed-form maximum likelihood estimates (MLEs) of variance components as well as fixed effect parameters in the cross-over design models are utilized in the proofs. The work exhibits the possibility to produce closed-form expressions of the influence using of the residuals in mixed models. A discussion on restrictions of the case-weighted perturbation schemes because of structural covariance is also given.