On 2013-07-15, at 4:00 AM, r-help-requ...@r-project.org wrote: > On 7/14/2013 3:05 PM, Rolf Turner wrote: >> On 15/07/13 08:57, Spencer Graves wrote: >> >> <SNIP> >>> >>> You may know that "mixed effects" is another term for "repeated >>> measurements". >> >> <SNIP> >> >> I must of course preface this comment with an "I am no expert" >> disclaimer, but I do not >> believe that this assertion is correct. It would be more correct, I >> believe, to say that >> repeated measurement models form a particular sub-class of mixed >> effects models. >> >> Those who *are* experts may well correct me if I am wrong about this. > > > Thanks for the clarification, Rolf. You are absolutely correct. > "Repeated measurements" refers to the sampling plan. "Mixed effects" > describes a form of mathematical modeling. There are balanced repeated > measures data sets where people do not have to worry about the > subtleties of mixed-effects modeling. An experiment with multiple > litters with several mice in at least some of the litters would call for > mixed-effects modeling. This would include "repeated measures" on the > litters but not the mice. > > > However, "I am no expert" on repeated measures / mixed-effects, > either
And you could have repeated measures within matched blocks (e.g., litters as the matched blocks, and some repeated measure---say trials---on the individual mice in each litter). H. D. Kimmel promoted such designs in the 1960s in a slim volume describing the analysis of two such designs. -- Please avoid sending me Word or PowerPoint attachments. See <http://www.gnu.org/philosophy/no-word-attachments.html> -Dr. John R. Vokey ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
