Constraint Grammar tutorial

May 14th, 2010 by donnek Leave a reply »

I’ve been doing some work over the past few weeks with the ESRC Centre for Research on Bilingualism at Bangor University, focussing on autoglossing their Welsh and Spanish conversation transcripts. As part of that, I’ve been using Constraint Grammar again as a possible approach to disambiguating words in the text.

Fran Tyers introduced me to CG, which is licensed under the GPL, when we were working on the Apertium Welsh translator 18 months ago. The Welsh grammar we ended up with, containing about 130 rules, was quite small by CG standards (the Portuguese CG grammar has around 9,000 rules), but was pretty effective.

In the course of revising and expanding that grammar, I thought it would consolidate my own learning to write a short tutorial, which might be useful to others as a gentler introduction to this very elegant and versatile system than the manual and howto. The result is a short note on Getting started with Constraint Grammar, using a Welsh sentence as the example text. The TeX source file is here, in case anyone wants to improve on it or extend it.

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