The Lemmatisation Task at the EVALITA 2011 Evaluation Campaign

摘要

This paper reports on the EVALITA 2011 Lemmatisation task, an initiative for the evaluation of automatic lemmatisation tools specifically developed for the Italian language. Despite lemmatisation is often considered a subproduct of a PoS-tagging procedure that does not cause any particular problem, there are a lot of specific cases, certainly in Italian and in some other highly inflected languages, in which, given the same lexical class, we face a lemma ambiguity. A relevant number of scholars and teams participated experimenting their systems on the data provided by the task organisers. The results are very interesting and the overall performances of the participating systems were very high, exceeding, on interesting cases, 99% of lemmatisation accuracy.