search for: posisson

...re intereted in, I will suppose it is something like: #Organims ~ Landscape + Soil + Depth + Species I suppose you have a table of with something like... Spec Lands Soil Depth #Organisms A 1 1 1 10 A 1 2 1 2 B 1 1 1 0 B 2 2 2 2 ... etc, Normally, the count of organisms in soil samples follows a posisson distribution, not a normal one. You should effectively check for normality in your final data table, including the zeroes. In fact, you can do an anova and then do some diagnostics plots, in R you would do something like (suppose your table is stored in an object called my data): mydata.lm <- l...