Re: [R] Getting vastly different results when running GLMs

2011-08-18 Thread Michael Dewey
At 16:43 17/08/2011, Luke Duncan wrote: Dear R gurus Response in line below I am analysing data from a study of behaviour and shade utilization of chimpanzees. I am using GLMs in R (version 2.13.0) to test whether shade/sun utilization is predicted by behaviour observed. I am thus interested

Re: [R] Getting vastly different results when running GLMs

2011-08-17 Thread Mark Difford
On Aug 17, 2011; 5:43pm Luke Duncan wrote: Hi Luke, The differences you are seeing are almost certainly due to different contrast codings: Statistica probably uses sum-to-zero contrasts whereas R uses treatment (Dunnett) contrasts by default. You would be well advised to consult a local statistic

[R] Getting vastly different results when running GLMs

2011-08-17 Thread Luke Duncan
Dear R gurus I am analysing data from a study of behaviour and shade utilization of chimpanzees. I am using GLMs in R (version 2.13.0) to test whether shade/sun utilization is predicted by behaviour observed. I am thus interested in whether an interaction of behaviour (as a predictor) and presence