I have a somewhat R and biostats question. I want to make boxplots with ggplot2 package and include in them the significance bars between groups. I have 4 groups in the boxplots. In my short statistic classes I always learned that I should do a OneWay ANOVA and then use multiple comparison tests (like Tukey HSD). However, in this package I can only use "t-test" or "wilcox.test" and I also learned that repeating t-tests in the same group of comparisons increases some kind of error.
Therefore, my question to you is if I can use the t-test to make the multiple comparisons between subgroups, or if I should perform ANOVA and the Tukey HSD for the multiple comparisons. If you think I should go for the Tukey, can you explain why the package only includes the T-test?
I appreciate any help you can give!