For the purposes of this experiment, we will consider the 8,214 samples in the mushroom data to be an exhaustive set of all the possible wild mushrooms. This is an important assumption, because it means that we do not need to hold some samples out of the training data for testing purposes. We are not trying to develop rules that cover unforeseen types of mushrooms; we are merely trying to find rules that accurately depict the complete set of known mushroom types. Therefore, we can
build and test the model on the same data.