Lemmatization of multi-word common noun phrases and named entities in Polish

Abstract

In the paper we present a tool for lemmatization of multi-word common noun phrases and named entities for Polish called PoLem1. The tool is based on a set of manually crafted rules and heuristics utilizing a set of dictionaries (including morphological, named entities and inflection patterns). The accuracy of lemmatization obtained by the tool reached 97.99% on a dataset with multi-word common noun phrases and 86.17% for case-sensitive evaluation on a dataset with named entities.