Notes

One factor two levels:

The simplest type of experiment is one in which we have one variable (factor) and two

levels. The method of analysis is then simply a t-test for two means,

Although this is how the data will be analyzed, it is important to try to make sure that the analysis is not contaminated by “lurking” variables.

One factor three or more levels:

There is no extension of a t-test to three or more levels, so we need a new method of analysis for such a case. Analysis of Variance can be used for this purpose.