Hi: Well, you fit a saturated model. How many degrees of freedom do you have left for error? The fact that the standard errors are so huge relative to the estimates is a clue.
Taking a look at your data, it's pretty clear that nation 3 is an outstanding outlier on its own. It is clearly - nay, blatantly - different from the other nations in the sample. Look at boxplot(fre ~ nation, data = data_Analysis) boxplot(sqrt(fre) ~ nation, data = data_Analysis) the latter to deal with the huge outlier near 1200 in the original data. Even on the square root scale, nation 3 sticks out like a sore thumb. 43/77 of your responses have zero frequency, so you should probably be looking into zero-inflated Poisson models and some of its relatives. Here is one citation to get you started: http://www.jstatsoft.org/v27/i08/paper Package VGAM also has functionality to fit these types of models. Using package sos, I typed # Install package sos first if you don't have it: library(sos) findFn('zero Poisson') which found 255 matches; you should find several packages that pertain to zero-inflated/zero-altered Poisson models. In the absence of the scientific background behind the data, the dominance of nation 3 may well mask more subtle effects among the other nations, so you might want to consider analyses with and without nation 3. HTH, Dennis On Tue, Jan 18, 2011 at 5:45 PM, Lao Meng <laomen...@gmail.com> wrote: > Hi all: > Here's a question about result of loglinear analysis. > There're 2 factors:area and nation.The raw data is in the attachment. > > I fit the saturated model of loglinear with the command: > glm_sat<-glm(fre~area*nation, family=poisson, data=data_Analysis) > > After that,I extract the coefficients: > result_sat<-summary(glm_sat) > result_coe<-result_sat$coefficients > > I find that all the coeffients are 1 or very near to 1. > > How does this happen?Why all the coeffients are 1 or very near to 1? > > Thanks! > > My best > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
