Building a Dictionary-Based Lemmatizer for Old Irish
Abstract : This paper explores the problem of developing NLP tools for morphologically rich and orthographically inconsistent classical languages. It is a case study of building a lemmatizer for Old Irish using only a dictionary and an unlabeled corpus as sources of data. At the current stage, the lemmatizer shows 76.31% average recall score on a corpus of ca. 100,000 tokens and is able to predict lemmas for out-of-vocabulary words. However, as it is the work in progress, the lemmatizer lacks some functionality such as disambiguation. There is no gold standard to measure accuracy yet either.
Keywords : lemmatisation, lemma, Old Irish, Middle Irish, Damerau-Levenshtein distance, unlabelled data, automatic morphological analysis.