Publication
Extraction and Normalization of Vague Time Expressions in German
Ulrike May; Karolina Zaczynska; Julian Moreno Schneider; Georg Rehm
In: Proceedings of the 17th Conference on Natural Language Processing (KONVENS 2021). Konferenz zur Verarbeitung natürlicher Sprache (KONVENS-2021), September 6-9, Düsseldorf, Germany, Pages 114-126, KONVENS 2021 Organizers, 2021.
Abstract
Existing datasets and methods that aim at the identification of time expressions in natural language text do not pay particular attention to expressions that are imprecise and that cannot be easily represented on a timeline. We call these vague time expressions (VTEs). We present an analysis of existing time extraction approaches and steps towards a novel scheme for the annotation of VTEs, developed using a corpus of German news articles. To the best of our knowledge, this work is the first to suggest an extension of the ISO standard TimeML with the goal of enabling the annotation of VTEs. In addition, we present a collection of 339 German VTEs as well as classification experiments on the news corpus with results from 60 up to 77 macro-avg. F1 score.