@inproceedings{bethard-parker-2016-semantically,
    title = "A Semantically Compositional Annotation Scheme for Time Normalization",
    author = "Bethard, Steven  and
      Parker, Jonathan",
    editor = "Calzolari, Nicoletta  and
      Choukri, Khalid  and
      Declerck, Thierry  and
      Goggi, Sara  and
      Grobelnik, Marko  and
      Maegaard, Bente  and
      Mariani, Joseph  and
      Mazo, Helene  and
      Moreno, Asuncion  and
      Odijk, Jan  and
      Piperidis, Stelios",
    booktitle = "Proceedings of the Tenth International Conference on Language Resources and Evaluation ({LREC}'16)",
    month = may,
    year = "2016",
    address = "Portoro{\v{z}}, Slovenia",
    publisher = "European Language Resources Association (ELRA)",
    url = "https://preview.aclanthology.org/landing_page/L16-1599/",
    pages = "3779--3786",
    abstract = "We present a new annotation scheme for normalizing time expressions, such as ``three days ago'', to computer-readable forms, such as 2016-03-07. The annotation scheme addresses several weaknesses of the existing TimeML standard, allowing the representation of time expressions that align to more than one calendar unit (e.g., ``the past three summers''), that are defined relative to events (e.g., ``three weeks postoperative''), and that are unions or intersections of smaller time expressions (e.g., ``Tuesdays and Thursdays''). It achieves this by modeling time expression interpretation as the semantic composition of temporal operators like UNION, NEXT, and AFTER. We have applied the annotation scheme to 34 documents so far, producing 1104 annotations, and achieving inter-annotator agreement of 0.821."
}