Analysis of Variance (ANOVA) and Multiple Comparisons in R (R Tutorial 4.6)
In this video you will learn to conduct one-way analysis of variance (ANOVA), a parametric method for comparing the means of two or more independent populations, and Kruskal Wallis one-way analysis of variance, a nonparametric equivalent to one-way analysis of variance.
In this tutorial we will first explain when it is appropriate to use one-way analysis of variance (ANOVA). We will start by examining the data visually by producing a boxplot. Then we will show you how to perform an analysis of variance in R using the "aov" command.
Later in the video, you will learn to view ANOVA table in R to get a more informative summary by using the "summary" command. You will also learn to use the "attributes" command to ask R what is stored in an object and then extract certain attributes from the object using the dollar sign ($). Moreover, this tutorial will demonstrate how to conduct multiple comparisons/pair-wise comparisons for the analysis of variance in R using the "TukeyHSD" command, to produce a visual display for the pair-wise comparisons of ANOVA using the "plot" command and to modify the plot from the default values.
You will also learn when to use Kruskal-Wallis one-way analysis of variance for data and how to produce Kruskal-Wallis one-way ANOVA using the "kruskal.test" command.
We recommend using the link below to download the dataset and practice on your own while watching this tutorial.
You can access and download the dataset that was used in this tutorial here: