Some comments on a class of simultaneous inference procedures in ancova

Abstract

Methods for constructing simultaneous confidence intervals for contrasts of treatment effects in analysis of covariance (ANCOVA) models are discussed and compared. A simple procedure is given by which, under a normality assumption made on the covariates, any method appropriate in an analysis of variance (ANOVA) may be applied to a corresponding ANCOVA by means of a simple adjustment of the required critical values. Some properties of this procedure are noted.

Keywords:

• analysis of covariance
• simulationeous inference
• joint confidence intervals
• T-method in ANCOVA
• Dunnett's method in ancova
• generalized studentized rang