Hi,
With glm, you add the binomial family:
model<-glm(biomass~Shore*Raked*Species+Shore*Fished*Species,family=binomial)
model


De : Christopher Cesar <C.Cesar@apemltd.co.uk>
À : "r-sig-ecology@r-project.org" <r-sig-ecology@r-project.org>
Envoyé le : Mercredi 24 Août 2011 12h02
Objet : [R-sig-eco] guidance required (GLM?)

Hi all,

I have carried out experimental removal of bivalves at 2 intertidal shores. Bivalves were removed by raking of surface sediments. I wish compare the biomass values of for a total of 8 species between the 2 shores

My 3 treatments are: Undisturbed Controls (Cont), Procedural Controls (Proc) and Experimetnally Fished (Fished).

As Fished and Proc have both experienced disturbance, I set the model using 2 factors as follows:

    Controls    Procedural    Fished
Raked    0        1        1
Fished0        0        1

As a newcomer to R (& stats!), I am unsure as to how to proceed.

i am currently adopting the approach

model<-glm(biomass~Shore*Raked*Species+Shore*Fished*Species)

And then run post-hoc adjusted pairwise comparisons between signifcant terms.

Does this look OK to you guys?

Many, many thanks

Chris



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