CHAID and Exhaustive CHAID Decision Trees // An implementation in base 'R' of the CHAID (Chi-squared Automatic Interaction Detection) decision tree algorithm of Kass (1980) doi:10.2307/2986296 and the Exhaustive CHAID variant of Biggs, de Ville, and Suen (1991) doi:10.1080/02664769100000005, as specified in the 'IBM SPSS' Statistics Algorithms documentation. Supports nominal, ordinal (with floating missing category), and continuous predictors, and nominal, ordinal, and continuous response variables using Pearson chi-squared, Goodman row-effects, and one-way ANOVA F tests respectively. Includes prediction, rule extraction, gains and lift analysis, validation on holdout data, and visualization via base graphics, 'Graphviz' DOT, 'plotly', and conversion to 'partykit' objects.