[R] Missing data and LME models and diagnostic plots

[Peter Flom]

I wrote

>>> I am puzzled by the performance of LME in situations where there are
>>> missing data.  As I 
>>> understand it, one of the strengths of this sort of model is how well it
>>> deals with missing 
>>> data, yet lme requires nonmissing data. 
>

Mark Difford replied

>You are confusing missing data with an unbalanced design. A strengths of LME
>is that it copes with the latter, which aov() does not.
>


Thanks for your reply, but I don't believe I am confused with respect to missing data in mixed models.  See e.g. Hedeker and Gibbons, Longitudinal Data Analysis, which repeatedly stresses that mixed models provide good estimates if the data are missing at random.

Regards

Peter



Peter L. Flom, PhD
Statistical Consultant
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