A Dataset of German Legal Documents for Named Entity Recognition
Table 3: Distribution of time expressions in the dataset
['[EMPTY]', 'DATE', 'DURATION', 'SET', 'TIME']
All court decisions were annotated automatically for time expressions using a customised version of HeidelTime [StroetgenGertz2013:LREjournal], which was adapted to the legal domain [Weissenhorn2018]. This version of Heideltime achieves an F1 value of 89.1 for partial identification and normalization. It recognizes four TIMEX3-types of time expressions [verhagen-etal-2010-semeval]: DATE, DURATION, SET, TIME. DATE describe a calendar date (‘23. July 1994’, ‘November 2019’, ‘winter 2001’ etc). It also includes expressions such as ‘present’, ‘former’ or ‘future’. DURATION describes time periods such as ‘two hours’ or ‘six years’. SET describes a set of times/periods (‘every day’, ‘twice a week’). TIME describes a time expression (‘13:12’, ‘tomorrow afternoon’). Expressions with a granularity less than 24 hours are of type TIME, all others are of type DATE. 94%̇ of which are of type DATE.