8.1 Analysis of covariance (ANCOVA)
Alright, to wrap up our crazy, eye-opening introduction to linear models we are going to unleash the power of ANCOVA, or the general linear model. Hopefully the power and limitations of this approach will be readily apparent to you. If not, we will talk about them a lot more so don’t worry.
ANCOVA is the way into the world of real, complex data analyses. It will serve as the foundation for the next several weeks in this course. Get to know it well, it is your friend. That said, ANCOVA is just another type of linear model (see Chapter title!), so it really doesn’t need it’s own book chapter except that it sounds scary to people. Plus, this is The Worst Stats Text eveR.
We won’t spend a tone of time on the development of these models as we covered most of the important ideas in Chapter 4. Instead, we are going to jump right in with an example. We’ll need the tidyverse for this chapter, as well as the data contained in crickets.txt. Go ahead and load the tidyverse now so you don’t forget.