[R-sig-ME] Mixed model parameterization

[Salvador Sánchez-Colón]

Hola Manuel:

If you are not interested in examining the between-hours or between-days variability, then you might consider analyzing the average of your hourly values and thus simplify the model. 

Best regards,

Salvador 

Salvador SÁNCHEZ-COLÓN 


> On May 20, 2019, at 8:54 AM, Manuel Spínola <mspinola10 using gmail.com> wrote:
> 
> Thank you very much Thierry.
> 
> I just only want to accomodate the nested repeated measure of my sampling.
> 
> I measure the index at the same plot, several times in an hour, several
> days and during several month.
> 
> 3 "habitats", within each habitat 12 plots, and on each plot I measured the
> index several times, within hours, several days and several months.
> 
> I am not interested in the evolution of the index in time, just to account
> for the repeated measure of my design (I measured the index hundreds of
> time on each plot).
> 
> Maybe I don't need to worry about hour, day and month?
> 
> Manuel
> 
> El lun., 20 may. 2019 a las 2:00, Thierry Onkelinx (<
> thierry.onkelinx using inbo.be>) escribió:
> 
>> Dear Manuel,
>> 
>> You'll need to think about the structure of your random effects. Your
>> current random effect structure is (1|plot) + (1|plot:hour) +
>> (1|plot:hour:day) + (1|plot:hour:day:month). Which might not be what you
>> had in mind.
>> 
>> Best regards,
>> 
>> ir. Thierry Onkelinx
>> Statisticus / Statistician
>> 
>> Vlaamse Overheid / Government of Flanders
>> INSTITUUT VOOR NATUUR- EN BOSONDERZOEK / RESEARCH INSTITUTE FOR NATURE AND
>> FOREST
>> Team Biometrie & Kwaliteitszorg / Team Biometrics & Quality Assurance
>> thierry.onkelinx using inbo.be
>> Havenlaan 88 bus 73, 1000 Brussel
>> www.inbo.be
>> 
>> 
>> ///////////////////////////////////////////////////////////////////////////////////////////
>> To call in the statistician after the experiment is done may be no more
>> than asking him to perform a post-mortem examination: he may be able to say
>> what the experiment died of. ~ Sir Ronald Aylmer Fisher
>> The plural of anecdote is not data. ~ Roger Brinner
>> The combination of some data and an aching desire for an answer does not
>> ensure that a reasonable answer can be extracted from a given body of data.
>> ~ John Tukey
>> 
>> ///////////////////////////////////////////////////////////////////////////////////////////
>> 
>> <https://www.inbo.be>
>> 
>> 
>> Op za 18 mei 2019 om 01:56 schreef Manuel Spínola <mspinola10 using gmail.com>:
>> 
>>> Dear list members,
>>> 
>>> I am measuring an index in plots, in different hours, different days, and
>>> different months in 3 different "habitats".
>>> 
>>> 12 plots by "habitats".
>>> 
>>> I would like to estimate the mean index in the 3 environments.
>>> 
>>> Is this model appropriate to achieve my goal?
>>> 
>>> model <- lmer(index ~  habitat + (1 | plot/hour/day/month), data = mydata,
>>> REML = FALSE)
>>> 
>>> Best,
>>> 
>>> Manuel
>>> 
>>> --
>>> *Manuel Spínola, Ph.D.*
>>> Instituto Internacional en Conservación y Manejo de Vida Silvestre
>>> Universidad Nacional
>>> Apartado 1350-3000
>>> Heredia
>>> COSTA RICA
>>> mspinola using una.cr <mspinola using una.ac.cr>
>>> mspinola10 using gmail.com
>>> Teléfono: (506) 8706 - 4662
>>> Personal website: Lobito de río <
>>> https://sites.google.com/site/lobitoderio/>
>>> Institutional website: ICOMVIS <http://www.icomvis.una.ac.cr/>
>>> 
>>>        [[alternative HTML version deleted]]
>>> 
>>> _______________________________________________
>>> R-sig-mixed-models using r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
>>> 
>> 
> 
> -- 
> *Manuel Spínola, Ph.D.*
> Instituto Internacional en Conservación y Manejo de Vida Silvestre
> Universidad Nacional
> Apartado 1350-3000
> Heredia
> COSTA RICA
> mspinola using una.cr <mspinola using una.ac.cr>
> mspinola10 using gmail.com
> Teléfono: (506) 8706 - 4662
> Personal website: Lobito de río <https://sites.google.com/site/lobitoderio/>
> Institutional website: ICOMVIS <http://www.icomvis.una.ac.cr/>
> 
>    [[alternative HTML version deleted]]
> 
> _______________________________________________
> R-sig-mixed-models using r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models