IOB Tagging Task

An IOB Tagging Task is a segmentation task that requires the tagging of string elements with a tag from the IOB tag set (that demarcate the Beginning, the Inside, or Outside the string segment).

• Context:
  • output: IOB Tagged Text.
  • …
• Example(s):
  • an IOB-based NP Chunking Task, such as [math]\displaystyle{ f }[/math]("Fluffy is a black cat.") ⇒ (Fluffy/B, is/O, a/O, black/B, cat/I, ./O).
  • …
• Counter-Example(s):
  • a POS Tagged Text.
• See: Named Entity Recognition Task, DNA Segmentation Task.

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References

2006

• (Sarawagi, 2006) ⇒ Sunita Sarawagi. (2006). “Efficient Inference on Sequence Segmentation Models.” In: Proceedings of the 23rd International Conference on Machine Learning (ICML 2006). doi:10.1145/1143844.1143944
  • QUOTE:Traditionally many of these applications have been artificially formulated as sequence labeling tasks at the expense of a loss of flexibility of features that can be exploited. This limitation is partly addressed by expanding the label set — for example, a popular choice in named entity recognition tasks (NER) is the Begin-Continue-End-Unique-other (BCEUO) encoding of entity labels (Borthwick et al., 1998), and in syntactic chunking tasks is the Begin-Inside-Outside (BIO) encoding of labels (Zhang et al., 2002).

1995

• (Ramshaw & Marcus, 1995) ⇒ Lance A. Ramshaw, and Mitch P. Marcus. (1995). “Text Chunking Using Transformation-based Learning.” In: Proceedings of the Third ACL Workshop on Very Large Corpora (WVLC 1995).
  • QUOTE:In the baseNP experiments aimed at non-recursive NP structures, we use the chunk tag set {I, O, B}, where words marked I are inside some baseNP, those marked O are outside, and the B tag is used to mark the left most item of a baseNP which immediately follows another baseNP. In these tests, punctuation marks were tagged in the same way as words.

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