Paper: Dependency Grammar Induction via Bitext Projection Constraints

ACL ID P09-1042
Title Dependency Grammar Induction via Bitext Projection Constraints
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 2009

Broad-coverage annotated treebanks nec- essary to train parsers do not exist for many resource-poor languages. The wide availability of parallel text and accurate parsers in English has opened up the pos- sibility of grammar induction through par- tial transfer across bitext. We consider generative and discriminative models for dependency grammar induction that use word-level alignments and a source lan- guage parser (English) to constrain the space of possible target trees. Unlike previous approaches, our framework does not require full projected parses, allowing partial, approximate transfer through lin- ear expectation constraints on the space of distributions over trees. We consider several types of constraints that range from generic dependency conservation to language-specific annota...