SaarlandValence

DELPH-IN meeting 2013: SIG on cross-linguistic Valence repositories

Lars Hellan

Delph-In-grammars typically have ‘complete’ verb-valence repositories, with a shared design, albeit not necessarily with the same type inventories – of course reflecting linguistic differences, but also differences in notational systems.

It will be an interesting linguistic resource if these repositories can be aligned, and useful for many purposes.

A way of 'operationalizing' such an alignment may be the creation of a multilingual valence database; the link below leads to a newly created such (technically constructed by Tore Bruland and me, using independently created resources), so far with three members, Norwegian, Spanish and Ga:

http://regdili.idi.ntnu.no:8080/multilanguage_valence_demo/multivalence

The best strategy for creating an aligned repository is presumably through the design of a ‘neutral’ notation, to which all the systems can map in equal fashion, and which is more friendly to the ‘human eye’ than many of the grammar internal codes; in particular it need not be restricted to the tdl format. The demo tries to implement this idea. An explanation of the demo, along with some of the material used in creating it, is found at http://typecraft.org/tc2wiki/Multilingual_Verb_Valence_Lexicon.

In principle only one file has to be created, namely a conversion from the grammar's lexical type inventory to the labels corresponding to it in the database and web demo. Together with the lexicon of the grammar, this file is sufficient for populating the database.

For ‘new’ languages, some code extensions will be called for – for instance, for Spanish, phenomena that immediately come up as distinct from Norwegian are ‘pro-drop’, clitic doubling, and the use of ‘à’ as a marker of objects.

To be done:

• In the Ga demo, each lexical item has an example, since this lexicon file comes from a Toolbox

project. In the Norwegian demo, there only is a representative example for the type in question; which is a bit bleak. I would be good if the slot Examples can be either populated, or occupied by hyperlinks to repositories with annotated examples (like TypeCraft), or even to parsers.

• The format of the demo does of course not require that the lexical types and resources come from

a grammar; it just is the enterprise considered presently. (Indeed, if filled in via some other route, a grammar might be partially constructible from the information there.) Among potentially interesting alternative provenance routes is the database of the ‘Leipzig Valency Classes project’ (acronym ‘ValPaL’), which will be accessible to free download from coming October on; interoperability between the systems has not been explored yet. Toolbox projects are another type of ‘sources’, also when not sifted via a grammar (as it is in the present case – Bender et al 2012 describe another Toolbox-LKB conversion that perhaps could be tried in the present setting of ‘being sifted through a grammar’).

An additional thing that can be done, once valence codes of different grammars are mapped onto a common code:

• Developing parallel testsuites, indexed according to the common code.

Something that perhaps could be done:

• Using the valence-bank in MT, for instance via a strategy of first identifying possible meaning

equivalents (via aligned WordNet, for instance), then search if any of them match in valence, and then – if so - do ‘isomorphic’ transfer as a first choice.

Well, these are possibilities, among many more …

Lars 270913