Use of Weighted Finite State Transducers in Part of Speech Tagging

This paper addresses issues in part of speech disambiguation using finite-state transducers and presents two main contributions to the field. One of them is the use of finite-state machines for part of speech tagging. Linguistic and statistical information is represented in terms of weights on transitions in weighted finite-state transducers. Another contribution is the successful combination of techniques -- linguistic and statistical -- for word disambiguation, compounded with the notion of word classes.Comment: uses psfig, ipamac

UNSUPERVISED PART OF SPEECH TAGGING FOR PERSIAN

Abstract In this paper we present a rather novel unsupervised method for part of speech (below POS) disambiguation which has been applied to Persian. This method known as Iterative Improved Feedback (IIF) Model, which is a heuristic one, uses only a raw corpus of Persian as well as all possible tags for every word in that corpus as input. During the process of tagging, the algorithm passes through several iterations corresponding to n-gram levels of analysis to disambiguate each word based on a previously defined threshold. The total accuracy of the program applying in Persian texts has been calculated as 93 percent, which seems very encouraging for POS tagging in this language

Using word class for part-of-speech disambiguation

This paper presents a methodology for improving part-of-speech disambiguation using word classes. We build on earlier work for tagging French where we showed that statistical estimates can be computed without lexical probabilities. We investigate new directions for coming up with different kinds of probabilities based on paradigms of tags for given words. We base estimates not on the words, but on the set of tags associated with a word. We compute frequencies of unigrams, bigrams, and trigrams of word classes in order to further refine the disambiguation. This ne

Using word class for part-of-speech disambiguation

This paper presents a methodology for improving part-of-speech disambiguation using word classes. We build on earlier work for tagging French where we showed that statistical estimates can be computed without lexical probabilities. We investigate new directions for coming up with different kinds of probabilities based on paradigms of tags for given words. We base estimates not on the words, but on the set of tags associated with a word. We compute frequencies of unigrams, bigrams, and trigrams of word classes in order to further refine the disambiguation. This new approach gives a more efficient representation of the data in order to disambiguate word part-of-speech. We show empirical results to support our claim. We demonstrate that, besides providing good estimates for disambiguation, word classes solve some of the problems caused by sparse training data. We describe a part-of-speech tagger built on these principles and we suggest a methodology for developing an adequate training corpus