Word order and discontinuities in dependency grammar

Natural languages are always difficult to parse. Two phenomena that constantly pose problems for different formalisms are word order - what part of a sentence has to be placed where - and discontinuities - words that belong together but are not placed into the same phrase. Dependency grammar, a linguistic formalism based on binary relations between words, is very adequate for handling both problems. A parser for dependency grammar together with its grammar writing formalism is described in this paper. Word order and discontinuities in Hungarian are handled based on this formalism

Word order and discontinuities in a dependency grammar for Hungarian

Natura] languages are always difficult to parse. Two phenomena that constantly pose problems for different formalisms are word order-what part of a sentence has to be placed where-and discontinuities-words that belong together but are not placed into the same phrase. Dependency grammar, a linguistic formalism based on binary relations between words, is very adequate for handling both problems. A parser for dependency grammar together with its grammar writing formalism is described in this paper. Word order and discontinuities in Hungarian are handled based on this formalism

Parsing as Reduction

We reduce phrase-representation parsing to dependency parsing. Our reduction is grounded on a new intermediate representation, "head-ordered dependency trees", shown to be isomorphic to constituent trees. By encoding order information in the dependency labels, we show that any off-the-shelf, trainable dependency parser can be used to produce constituents. When this parser is non-projective, we can perform discontinuous parsing in a very natural manner. Despite the simplicity of our approach, experiments show that the resulting parsers are on par with strong baselines, such as the Berkeley parser for English and the best single system in the SPMRL-2014 shared task. Results are particularly striking for discontinuous parsing of German, where we surpass the current state of the art by a wide margin

Message-Passing Protocols for Real-World Parsing -- An Object-Oriented Model and its Preliminary Evaluation

We argue for a performance-based design of natural language grammars and their associated parsers in order to meet the constraints imposed by real-world NLP. Our approach incorporates declarative and procedural knowledge about language and language use within an object-oriented specification framework. We discuss several message-passing protocols for parsing and provide reasons for sacrificing completeness of the parse in favor of efficiency based on a preliminary empirical evaluation.Comment: 12 pages, uses epsfig.st

Statistical parsing of morphologically rich languages (SPMRL): what, how and whither

The term Morphologically Rich Languages (MRLs) refers to languages in which significant information concerning syntactic units and relations is expressed at word-level. There is ample evidence that the application of readily available statistical parsing models to such languages is susceptible to serious performance degradation. The first workshop on statistical parsing of MRLs hosts a variety of contributions which show that despite language-specific idiosyncrasies, the problems associated with parsing MRLs cut across languages and parsing frameworks. In this paper we review the current state-of-affairs with respect to parsing MRLs and point out central challenges. We synthesize the contributions of researchers working on parsing Arabic, Basque, French, German, Hebrew, Hindi and Korean to point out shared solutions across languages. The overarching analysis suggests itself as a source of directions for future investigations