On Mon, 26 Jun 2006, Bruno L. Giordano wrote: > Hello, > > with 4 different linear mixed models (continuous dependent) I find that my > residuals do not follow the normality assumption (significant Shapiro-Wilk > with values equal/higher than 0.976; sample sizes 750 or 1200). I find, > instead, that my residuals are really well fitted by a t distribution with > dofs' ranging, in the different datasets, from 5 to 12. > > Should this be considered such a severe violation of the normality > assumption as to make model-based inferences invalid?
For some aspects, yes. Given that R provides you with the means to fit robust linear models, why not use them and find out if they make a difference to the aspects you are interested in? -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
