Chapter 4
Testing More than Two Samples
IN THIS CHAPTER
Understanding why multiple t-tests won’t work
Analyzing variance
Taking the next step after an ANOVA
Working with repeated measures
Performing a trend analysis
Statistics would be limited if you could only make inferences about one or two samples. In this chapter, I discuss the procedures for testing hypotheses about three or more samples. I show what to do when samples are independent of one another, and what to do when they’re not. In both cases, I discuss what to do after you test the hypotheses. I also discuss R functions that do the work for you.
Testing More than Two
Imagine this situation. Your company asks you to evaluate three different methods for training its employees to do a particular job. You randomly assign 30 employees to one of the three methods, resulting in 10 employees in the Method 1 group, 10 different employees in the Method 2 group, and 10 more in the Method 3 group. Your plan is to train and ...
Get R All-in-One For Dummies now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
