GUTime - Adding TIMEX3 Tags

The GUTime tagger, developed at Georgetown University, extends the capabilities of the TempEx tagger (Mani and Wilson, 2000). TempEx, developed at MITRE, is aimed at the ACE TIMEX2 standard (timex2.mitre.org) for recognizing the extents and normalized values of time expressions. TempEx handles both absolute times (e.g., June 2, 2003) and relative times (e.g., Thursday) by means of a number of tests on the local context. Lexical triggers like today, yesterday, and tomorrow, when used in a specific sense, as well as words which indicate a positional offset, like next month, last year, this coming Thursday are resolved based on computing direction and magnitude with respect to a reference time, which is usually the document publication time.

GUTime extends TempEx to handle time expressions based on the TimeML TIMEX3 standard, which allows a functional style of encoding offsets in time expressions. For example, last week could be represented not only by the time value but also by an expression that could be evaluated to compute the value, namely, that it is the week preceding the week of the document date. GUTime also handles a variety of ACE TIMEX2 expressions not covered by TempEx, including durations, a variety of temporal modifiers, and European date formats. GUTime has been benchmarked on training data from the Time Expression Recognition and Normalization task (timex2.mitre.org/tern.html) at .85, .78, and .82 F-measure for timex2, text, and val fields respectively.

An example of GUTime output is shown below, the added TIMEX3 is in bold type.

References

Inderjeet Mani and George Wilson. 2000. Processing of News. Proceedings of the 38th Annual Meeting of the Association for Computational Linguistics (ACL2000). Pages 69-76.