In this section we discuss a method called **Analysis of Variance** (ANOVA), which
allows us to compare several population means.

More specifically, we discuss the so-called **one-way analysis of variance**. This
type of ANOVA compares the means of a variable that result from the
classification by *one* other variable, called the
**factor**. To illustrate the concept let us design a
simple example. Say, we compare the mean annual salary of German
residents grouped by federal sates (by the way there are sixteen federal states, which are collectively
referred to as “Bundesländer”). Then we would get 16 means of annual
salaries, one for each federal state. Thus, in this example the state
variable is that one particular classification variable, the so-called
factor.

Note:The one-way analysis of variance is the generalization of the pooledt-test to more than two populations.

**Citation**

The E-Learning project SOGA-R was developed at the Department of Earth Sciences by Kai Hartmann, Joachim Krois and Annette Rudolph. You can reach us via mail by soga[at]zedat.fu-berlin.de.

You may use this project freely under the Creative Commons Attribution-ShareAlike 4.0 International License.

Please cite as follow: *Hartmann,
K., Krois, J., Rudolph, A. (2023): Statistics and Geodata Analysis
using R (SOGA-R). Department of Earth Sciences, Freie Universitaet Berlin.*