SACR: A Drag-and-Drop Based Tool for Coreference Annotation
Résumé
This paper introduces SACR, an easy-to-use coreference chain annotation tool, which is used to annotate large corpora for Natural Language Processing applications. Coreference annotation is usually considered as costly both in terms of time and human resources. So, in order to find the easiest annotation strategy, we will first of all compare several annotation schemes implemented in existing tools. Since interface ergonomics is also an important part of our research, we then focus on identifying the most helpful features to reduce the strain for annotators. In the next section of the paper, we present SACR in details. This tool has been developped specifically for coreference annotation, and its intuitive user interface has been designed to facilitate and speed up the annotation process, making SACR equally suited for students, occasional and non-technical users. In order to create coreference chains, elements are selected by clicking on the corresponding tokens. Coreference relations are then created by drag-and-dropping expressions one over the other. Finally, color frames around marked expressions help the user to visualize both marked expressions and their relations. SACR is open source, distributed under the terms of the Mozilla Public License, version 2.0, and freely available online.