Comprehensive Annotation of Various Types of Temporal Information on the Time Axis

In order to make the temporal interpretation of text, there have been many studies linking event and temporal information, such as temporal ordering of events and timeline generation. To train and evaluate models in these studies, many corpora that associate event information with time information have been developed. In this paper, we propose an annotation scheme that anchors expressions in text to the time axis comprehensively, extending the previous studies in the following two points. One of the points is to annotate not only expressions with strong temporality but also expressions with weak temporality, such as states and habits. The other point is that various types of temporal information, such as frequency and duration, can be anchored to the time axis. Using this annotation scheme, we annotated a subset of Kyoto University Text Corpus. Since the corpus has already been annotated predicate-argument structures and coreference relations, it can be utilized for integrated information analysis of events, entities and time.