Factorial ANOVA is a method used to study the effects of different factors on an experiment. When all factors have only two levels, it's easier to understand the main effects and interactions. These designs, called 2k factorial designs, offer many possibilities for experiments. By using a full factorial ANOVA, we can determine which effects are important. In some cases, we may need to control outside factors that could affect our results. Full factorial designs with more than four factors require a lot of experiments to be accurate.