A Dictionary-and Corpus-Independent Statistical Lemmatizer for Information Retrieval in Low Resource Languages

摘要

We present a dictionary- and corpus-independent statistical lemmatizer StaLe that deals with the out-of-vocabulary (OOV) problem of dictionary-based lemmatization by generating candidate lemmas for any inflected word forms. StaLe can be applied with little effort to languages lacking linguistic resources. We show the performance of StaLe both in lemmatization tasks alone and as a component in an IR system using several datasets and query types in four high resource languages. StaLe is competitive, reaching 88-108 % of gold standard performance of a commercial lemmatizer in IR experiments. Despite competitive performance, it is compact, efficient and fast to apply to new languages.