rm(list=ls(all=TRUE)) signspd <- read.csv("http://www.stat.ufl.edu/~winner/data/carspeed.csv") attach(signspd); names(signspd) interaction.plot(Trt,Subject,accelerate) Trt <- factor(Trt, levels=1:3, labels=c("No SRM", "LSRM", "TRSM")) Subject <- factor(Subject) options(contrasts=c("contr.sum","contr.poly")) speed.mod1 <- aov(accelerate ~ Subject + Trt) anova(speed.mod1) summary.lm(speed.mod1) TukeyHSD(speed.mod1,"Trt") e.mod1 <- resid(speed.mod1) yhat.mod1 <- predict(speed.mod1) plot(yhat.mod1,e.mod1) qqnorm(e.mod1); qqline(e.mod1) shapiro.test(e.mod1) stripchart(e.mod1 ~ Subject, xlab="Residuals", ylab="Subject") friedman.test(accelerate ~ Trt | Subject) rm(list=ls(all=TRUE))