On different approaches to syntactic analysis into bi-lexical dependencies : An empirical comparison of direct, PCFG-based, and HPSG-based parsers

We compare three different approaches to parsing into syntactic, bilexical dependencies for English: a ‘direct’ data-driven dependenci parser, a statistical phrase structure parser, and a hybrid, ‘deep’ grammar-driven parser. The analyses from the latter two are postconverted to bi-lexical dependencies. Through this ‘reduction’ of All three approaches to syntactic dependency parsers, we determine empirically what performance can be obtained for a common set of dependenci types for English; in- and out-of-domain experimentation ranges over diverse text types. In doing so, we observe what trade-offs apply along three dimensions: accuracy, efficiency, and resilience to domain variation. Our results suggest that the hand-built grammar in one of our parsers helps in both accuracy and cross-domain parsing performance. When evaluated extrinsically in two downstream tasks – negation resolution and semantic dependency parsing – these accuracy gains do sometimes but not always translate into improved end-to-end performance.