Parsing Arabic Using Treebank-based LFG Resources

Lamia Tounsi, Mohammed Attia, and Josef van Genabith

Abstract

Proceedings of LFG09; CSLI Publications On-line

In this paper we present initial results on parsing Arabic using treebank-based parsers and automatic LFG f-structure annotation methodologies. The Arabic Annotation Algorithm A3 (Tounsi et al., 2009) exploits the rich functional annotations in the Penn Arabic Treebank (ATB) (Bies and Maamouri, 2003), (Maamouri and Bies, 2004) to assign LFG f-structure equations to trees. For parsing, we modify Bikel's (2004) parser to learn ATB functional tags and merge phrasal categories with functional tags in the training data. Functional tags in parser output trees are then "unmasked" and available to A3 to assign f-structure equations.

We evaluate the resulting f-structures against the DCU250 Arabic gold standard dependency bank (Al-Raheb and al., 2006). Currently we achieve a dependency f-score of 77%.