So sorry, My response variable is "site" (not "gender"!). The selection process was:
> str(data) 'data.frame': 1003 obs. of 5 variables: $ site : Factor w/ 2 levels "0","1": 1 1 1 1 1 1 1 1 1 1 ... $ sex : Factor w/ 2 levels "0","1": NA NA NA NA 1 NA NA NA NA NA ... $ age : Factor w/ 2 levels "0","1": 1 1 1 1 1 1 1 1 1 1 ... $ cohort: Factor w/ 10 levels "1999","2000",..: 10 10 10 10 10 10 10 10 10 10 ... $ birth : Factor w/ 3 levels "5","6","7": 3 3 2 2 2 2 2 2 2 2 ... > datasex<-subset(data, sex !="NA") *Here below the structure of the analysis and only the anova.glm of the last, selected model, mod4: * >mod1 <- glm(site ~ sex + birth + cohort + sex:birth, data=datasex, family = binomial) >summary(mod1) >anova(mod1,update(mod1,~.-sex:birth),test="Chisq") >mod2 <- glm(site ~ sex + birth + cohort, data=datasex, family = binomial) >summary(mod2) >anova(mod2,update(mod2,~.-sex),test="Chisq") >mod3 <- glm(site ~ birth + cohort, data=data, family = binomial) >summary(mod3) >anova(mod3,update(mod3,~.-birth),test="Chisq") >mod4 <- glm(site ~ cohort, data=data, family = binomial) >summary(mod4) >anova(mod4,update(mod4,~.-cohort),test="Chisq") Analysis of Deviance Table Model 1: site ~ cohort Model 2: site ~ 1 Resid. Df Resid. Dev Df Deviance P(>|Chi|) 1 993 1283.7 2 1002 1368.2 -9 -84.554 2.002e-14 *** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 *My question:* In this case, the Chi2 value would be the difference in deviance between models and d.f. the difference in d.f. (84.554 and 9)? In other words may I correctly assess: /"cohorts were unevenly distributed between sites ( Chi2=84.5, df=9, p < 0.001)"/? -- View this message in context: http://r.789695.n4.nabble.com/Chi-square-value-of-anova-binomialglmnull-binomglmmod-test-Chisq-tp4632293p4632312.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
