Example – identifying poisonous mushrooms with rule learners
Each year, many people fall ill and sometimes even die from ingesting poisonous, wild mushrooms. Since many mushrooms are very similar to each other in appearance, occasionally even experienced mushroom gatherers are poisoned.
Unlike the identification of harmful plants such as a poison oak or poison ivy, there are no clear rules like "leaves of three, let them be" for identifying whether a wild mushroom is poisonous or edible. Complicating matters, many traditional rules such as "poisonous mushrooms are brightly colored" provide dangerous or misleading information. If simple, clear, and consistent rules were available for identifying poisonous mushrooms, they could save the lives of foragers.
As one of the strengths of rule-learning algorithms is the fact that they generate easy to understand rules, they seem like an appropriate fit for this classification task. However, the rules will only be as useful as they are accurate.