Hello everyone, I wonder if sample size?can be used as weight? in a weighted mixed model. Or should I use just the inverse of the variance? For example, the class'lmer' in the 'lme4' package?have an option 'weights' (as in the class 'lm' of 'stats'). In the help of lme4 there is an example using 'herd size' as weight in a mixed model. ? ?So, if I have a measurement data (eg height) of 10 groups (sample size ranging from?30 to 3000 individuals?for each group) can?I??use this number (N, sample size) in the 'weights' option? Is this wrong? ? Finally, what to do if the results (coefficients) of weighing by 'inverse of the variance' or by 'sample size' are very different, even opposite? Thank you very much in advance David