Department of Computer Science University of Arizona Tucson, AZ 85721 {dhewlett,cohen}@ Abstract Several results in the word segmentation literature suggest that description length provides a useful estimate of segmentation quality in fully unsupervised settings. However, since the space of potential segmentations grows exponentially with the length of the corpus, no tractable algorithm follows directly from the Minimum Description Length (MDL) principle. Therefore, it is necessary to generate a set of candidate segmentations and select between them according to the MDL principle. We evaluate several algorithms for generating these candidate segmentations on a range of natural language corpora, and show that the.