Mixed model parameterization
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]]
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