18 Introduction
18.1 Objectives
Aim: To introduce R commands for carrying out two-way ANOVA and linear regression with grouped data/ANCOVA
By the end of this practical participants should be able to achieve the following:
- Carry out a two-way ANOVA using R and interpret the output
- Analyse linear regression with grouped data (ANCOVA)
18.2 Background
This practical focuses on the implementation of various statistical tests relating to multiple predictor variables in R. It does not focus on the underlying theory of the tests (although the demonstrators will be happy to answer any questions that you may have).
For each test there will be a section explaining how to perform the test, a section explaining the results that have been output to the screen, and an exercise for you to complete relating to the test itself.