karate <- read.table("http://www.stat.ufl.edu/~winner/sta4211/karate_board1.dat", header=T) pdf("E:\\blue_drive\\Rmisc\\graphs\\karate_board.pdf") attach(karate) names(karate) kb.mod1 <- lm(Y ~ X1 + X2 + X3 + X4 + X1X4 + X2X4 + X3X4) anova(kb.mod1) kb.mod2 <- lm(Y ~ X1 + X2 + X3 + X4) anova(kb.mod2) kb.mod3 <- lm(Y ~ X4 + X1X4 + X2X4 + X3X4) anova(kb.mod3) kb.mod4 <- lm(Y ~ X1 + X2 + X3 + X1X4 + X2X4 + X3X4) anova(kb.mod4) anova(kb.mod2,kb.mod1) anova(kb.mod3,kb.mod1) anova(kb.mod4,kb.mod1) kb.mod5 <- aov(Y ~ factor(Wood) + factor(Board)) anova(kb.mod5) drop1(kb.mod5) TukeyHSD(kb.mod5) dev.off()