Recognition of Polish Temporal Expressions

In this article we present the result of the recent research in the recognition of Polish temporal expressions. The temporal information extracted from the text plays major role in many information extraction systems, like question answering, event recognition or discourse analysis. We prepared a broad description of Polish temporal expressions, called PLIMEX. It is based on the state-of-the-art solutions for English, mostly TimeML specification. This solution can be used for the extraction of events and their attributes, in order to anchor events in time and to reason about the persistence of events. We prepared the annotation guidelines and we annotated all documents in Polish Corpus of Wrocław University of Technology (KPWr) using our specification. Here we describe results achieved by Liner2 machine learning system, adapted to recognise Polish temporal expressions.