Guy Lebanon, John Lafferty
A distance-based conditional model on the ranking poset is presented for use in classiﬁcation and ranking. The model is an extension of the Mallows model, and generalizes the classiﬁer combination methods used by several ensemble learning algorithms, including error correcting output codes, discrete AdaBoost, logistic regression and cranking. The algebraic structure of the ranking poset leads to a simple Bayesian inter- pretation of the conditional model and its special cases. In addition to a unifying view, the framework suggests a probabilistic interpretation for error correcting output codes and an extension beyond the binary coding scheme.