Message-ID: <CAJuCY5zxyaES-zCKBL_0szqiecfgw5NT8cao8DW1G1vpi9aL+w@mail.gmail.com>
Date: 2019-05-20T08:00:03Z
From: Thierry Onkelinx
Subject: Mixed model parameterization
In-Reply-To: <CABkCotRU8z=OpntgwdBxw+c9G=SH1_KyCZwUUEZmr_Rn1Es2Ww@mail.gmail.com>
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
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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
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<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/>
>
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>
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>
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