[R] Book recomendation: Repeated Measurements

Vokey, John vokey at uleth.ca
Mon Jul 15 19:41:59 CEST 2013


On 2013-07-15, at 4:00 AM, r-help-request at 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.

--
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-Dr. John R. Vokey



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