An Efficient Algorithm for Unsupervised Word Segmentation with Branching Entropy and MDL

Valentin Zhikov, Hiroya Takamura, Manabu Okumura

Abstract: This paper proposes a fast and simple unsupervised word segmentation algorithm that utilizes the local predictability of adjacent character sequences, while searching for a least-effort representation of the data. The model uses branching entropy as a means of constraining the hypothesis space, in order to efficiently obtain a solution that minimizes the length of a two-part MDL code. An evaluation with corpora in Japanese, Thai, English, and the "CHILDES" corpus for research in language development reveals that the algorithm achieves an accuracy, comparable to that of the state-of-the-art methods in unsupervised word segmentation, in a significantly reduced computational time.