Nordic Treebank Network Meeting

Tartu, 8-10 September 2004

Day 1: Working Group Sessions and Discussion

Tools and Resources (TIGER-XML)

In the TIGER-XML session at the Tartu meeting, the network members voted to accept proposals 1.1 on character encoding, 1.2 on intersegmental links, and 1.3 on glosses (cf. http://www.id.cbs.dk/~mtk/ntn/tiger-xml.html) as recommendations in their current form. For the other proposals on the ballot, the network members voted to set up the following working groups for each proposal:

• 1.4. Dependency graphs: Joakim Nivre, Heli Uibo, Matthias Kromann, Søren Harder.
• 1.5. External sources (text, speech, video): Koenrad de Smedt, Janne Bondi Johannesen, Matthias Kromann, Manne Miettinen.
• 1.6. Argument structure: Joakim Nivre, Eckhard Bick, Søren Harder.
• 2.1. Segments: Nobody volunteered. Unless somebody volunteers, the network will not make a recommendation within this area.
• 2.2. Alignment: Martin Volk, Yvonne Samuelsson, Matthias Kromann, Søren Harder, Eckhard Bick, Lars Nygaard.

Parallel Treebank

Martin Volk presented two projects about parallel treebanks that were done by PhD students as part of the Treebank Course. Both were on the topic of transfering information from a treebank in one language (e.g. EN) to a parallel language (e.g. Amharic) .

Atelach Alemu has done a project on "Projecting Dependency Parses - English to Amharic". She has parsed English Sofie sentences and wrote a program to transfer the information to Amharic. Her conclusions were rather negative. However, Svetoslav Marinov (Skövde) has done a project on "(Semi-)Automatic transfer of syntactic information" from Swedish to Bulgarian. He transfered the dependency information computed for Swedish by the Växjö group to Bulgarian. And his recall and precision values were encouraging.

In this section we also presented three other projects that were done by PhD students but were not related to parallel treebanks:

• Johan Hall and Jens Nilsson (Växjö University) worked on "Converting dependency treebanks to MALT-XML"
• Kaarel Kaljurand (Tartu University) worked on "Checking treebank consistency"
• Henrik Oxhammar and Hans Hjelm (Stockholm University) worked on "Guidelines for Named Entity Markup in ANNOTATE"

• They have annotated the first chapter of Sofie's World both for German and Swedish with flat constituent structure trees according to the NEGRA/TIGER guidelines.
• They used the German chunker to annotate the Swedish sentences which saved more than 50% of the annotation time (compared to completely manual annotation of the Swedish sentences).
• They have developed a program to "deepen" the flat tree structures by automatically adding new nodes. This deepening makes the trees more consistent, linguistically more plausible, and enables finer alignment between the trees.
• They have written a program to exploit automatic word alignment information (as obtained by Jörg Tiedemann) for phrase alignment and were quite pleased with the evaluation results.
• They have written a program to visualize node alignments based on the SVG trees exported from TIGER-Search and the alignment information in an XML file.

Janne Bondi Johannessen compiled a status list of the annotated Sofie sentences in the various languages. She will follow up on this and see that the various groups submit their annotations to the online database in Oslo. We also asked that the problem with the display of crossing branches need be solved. One option would be to use the SVG trees from TIGER-Search (instead of a local tree display).

Various other research topics with respect to Parallel Treebanks were discussed, but no actions were taken:

• A search tool over parallel treebanks is needed.
• Alignment between different annotation formats should be explored.
• Alignment between differing languages should be explored (e.g. Swedish-Estonian alignment).
• The interpretation of alignment information as transfer rules in Machine Translation seems interesting.

Notational Harmonization (VISL)

In the session on notational harmonization, Eckhard presented the VISL category system providing definitions for the individual form and function categories, with a special focus on co-ordination and the stacking notation. Joakim presented a VISL-transformation of Swedish dependency treebank edge labels.

The following actions were agreed upon:

• Eckhard will produce a full list of VISL categories for the Sophie web site.
• Everybody will provide a VISL style version of their Sophie data, with the possibility of publishing both VISL and native versions in parallel at the Sophie website.
• On top of the existing f (free) and b (valency bound), the following lower case prefix letters for VISL categories were suggested, though not formally decided:
  • t = topic, e.g. tS (topic subject: *Peter*, han er kedelig.)
  • s = secondary, e.g. sOd (secondary edge object relation)
  • g = gapping, e.g. gS (gapping subject, without a verb: Peter bor i Rom, *Hans* i London

Spoken Language and Discourse

The network decided to set down a working group consisting of Janne Bondi Johanneson and Matthias Kromann for planning NTN's work on spoken language treebanks. The primary task for this working group is:

• To plan a spoken language task where NTN members are asked to create a treebank for a small sample of spoken language transcriptions. The purpose of this task is to start a discussion on spoken language treebanks within the NTN.
• To contact the organizers of NODALIDA about the possibility of arranging a treebank workshop in connection with NODALIDA. The workshop should have a public session on open issues in spoken language treebank creation, a session on other public issues (eg, parallel treebanks), and a (possibly private) NTN session where we can plan the upcoming activities within the network.
• To plan the NODALIDA workshop, including examining the possibility of inviting 1-2 keynote speakers in the spoken language treebank session. The plans must be circulated before the TLT meeting in Tübingen.

Day 2: Planning

• TIGER-XML: All the tasks, working groups and deadlines proposed in the working group session (see above) were agreed upon.
• Publication efforts:
  • The network will produce a white paper on treebanking in the Nordic countries for the yearbook of the Nordic Language Technology Program. An editing committee consisting of Joakim, Koenraad and Martin will circulate drafts during the month of October and produce a final version before the end of October.
  • The network will put together a book proposal focusing on the Sophie parallel treebank. An editing committee consisting of Eckhard, Heli and Martin will produce a first version by 1 December.
  • Contributions to the yearbook of the Nordic Language Technology Program should be sent to the local documentation centers before the end of October. In addition, contributors should send their submissions to Joakim, who will inform Henrik about what contributions to expect from the network. Everyone who contributes a paper to the TLT workshop is encouraged to publish the paper also in the yearbook.
• Parallel treebank and notational harmonization: It was decided that everyone who contributes to the Sophie parallel treebank should try to
  • produce a version using the VISL categories,
  • annotate the entire first two chapters (with alignment to the Norwegian original),
  before December 31.
• Spoken language and discourse: The plans proposed in the working group session (see above) were agreed upon.
• TLT 2004: Each network site should send a message to Joakim before 5 October indicating how many participants they want to send to TLT 2004 in Tübingen. It was agreed that priority should be given to
  • sites contributing papers to the workshop,
  • sites that have been active in the network in general.
• Network activities after December 2004. Three decisions were reached:
  • We will apply for an extension of the network's duration to 1 July 2005, aiming to have a final meeting in conjunction with NoDaLiDa and the General Seminar of the Nordic Language Technology Program in Joensuu in May 2005.
  • We will try to have yearly meetings also after 2005. The next meeting after Joensuu is tentatively planned to be in Bergen in 2006 with support from the Trepil project.
  • We will maintain the mailing list also after 1 July 2005.

Participants

Pictures

• Pictures (thanks to Kimmo Koskenniemi)
• More pictures (thanks to Gunnar Hrafn Hrafnbjargarson and Janne Bondi Johannessen)