Smoothing and compression with stochastic k-testable tree languages

In this paper, we describe some techniques to learn probabilistic k-testable tree models, a generalization of the well known k-gram models, that can be used to compress or classify structured data. These models are easy to infer from samples and allow for incremental updates. Moreover, as shown here, backing-off schemes can be defined to solve data sparseness, a problem that often arises when using trees to represent the data. These features make them suitable to compress structured data files at a better rate than string-based methods.The Spanish Comisión Interministerial de Ciencia y Tecnología through Grants TIC2003-08681-C02 and TIC2003-08496-C04