Visualizing Trees and Forests

Abstract

Tree-basedmodels provide an appealing alternative to conventional models formany reasons. They are more readily interpretable, can handle both continuous and categorical covariates, can accommodate data with missing values, provide an implicit variable selection, and model interactionswell. Most frequently used tree-basedmodels are classification, regression, and survival trees. Visualization is important in conjunction with treemodels because in their graphical formthey are easily interpretable even without special knowledge. Interpretation of decision trees displayed as a hierarchy of decision rules is highly intuitive.