On May 20, 2019, at 8:54 AM, Manuel Sp?nola <mspinola10 at 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 at inbo.be>) escribi?:
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 at 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 Sp?nola <mspinola10 at 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 Sp?nola, Ph.D.*
Instituto Internacional en Conservaci?n y Manejo de Vida Silvestre
Universidad Nacional
Apartado 1350-3000
Heredia
COSTA RICA
mspinola at una.cr <mspinola at una.ac.cr>
mspinola10 at gmail.com
Tel?fono: (506) 8706 - 4662
Personal website: Lobito de r?o <
https://sites.google.com/site/lobitoderio/>
Institutional website: ICOMVIS <http://www.icomvis.una.ac.cr/>
[[alternative HTML version deleted]]