Dear Sirs What is the best aproximation to the standardized normal distribution: necessidade = c("sem necessidade","com necessidade") tipo =c("CE-1", "CE-2", "CE-3") dados=c(20,34,44,69,9,3) Tabela =cbind(expand.grid(list(Necessidade=necessidade, Tipo=tipo)), count=dados) Tabela.array=tapply(Tabela$count, Tabela[,1:2], sum) ni = rowSums(Tabela.array) nj = colSums(Tabela.array) n = sum(Tabela.array) fit.glm=glm(count~Necessidade+Tipo, data=Tabela, family=poisson) ############# chisq.test(Tabela.array) ############ resid.pear=residuals(fit.glm, type="pearson") %%% This one? (no residuals are outside the range -1,96 to 1,96 ########### resid.pear.mat=matrix(resid.pear, nc=3, byrow=F,dimnames=list(c("sem necessidade","com necessidade"),c("CE-1", "CE-2","CE-3"))) n*resid.pear.mat/sqrt(outer(n-ni,n-nj,"*")) %%% Or this one? (residuals are outside the range -1,96, 1,96) Thanks Jorge