Paper: Parsing Coordinations

ACL ID E09-1047
Title Parsing Coordinations
Venue Annual Meeting of The European Chapter of The Association of Computational Linguistics
Session Main Conference
Year 2009

The present paper is concerned with sta- tistical parsing of constituent structures in German. The paper presents four ex- periments that aim at improving parsing performance of coordinate structure: 1) reranking the n-best parses of a PCFG parser, 2) enriching the input to a PCFG parser by gold scopes for any conjunct, 3) reranking the parser output for all possi- ble scopes for conjuncts that are permissi- ble with regard to clause structure. Exper- iment 4 reranks a combination of parses from experiments 1 and 3. The experiments presented show that n- best parsing combined with reranking im- proves results by a large margin. Provid- ing the parser with different scope possi- bilities and reranking the resulting parses results in an increase in F-score from 69.76 for the baseline to 74.6...