Dear all,
We have data from a study with 6 strata. The small strata are oversampled and the large strata undersampled. The locations are revisited every three years. Our basic model is glmer(Count ~ factor(Year) + (1|Location), family = poisson).
Can we take the over- and undersampling into account with the weights argument? Do we have to standardise the weights? E.g. the sum of all the weights = 1, or the sum of the weights per 3 year cycle = 1, or the sum of the weights per year = 1
Best regards,
Thierry
----------------------------------------------------------------------------
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek
team Biometrie & Kwaliteitszorg
Gaverstraat 4
9500 Geraardsbergen
Belgium
Research Institute for Nature and Forest
team Biometrics & Quality Assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be
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