Classification and regression trees (CART) are a computer–intensive data–mining tool originally designed for analyzing vast databases of often incomplete data, with an aim to find financial frauds, suitable candidates for loans, potential customers, and other uncertain outputs. Searching for potential invasive species and their traits responsible for invasiveness, predicting their potential distributions in regions where they are not native, or identifying factors that distinguish invasible communities from those that resist invasion are similar risk assessments. This is perhaps one reason why CART and related methods are becoming increasingly popular in the field of invasion biology. Identifying homogeneous groups with high or low risk and constructing rules for making predictions about individual cases is, in essence, the same for financial credit scoring as for pest risk assessment. In both cases, one searches for rules that can be used to predict uncertain future events.