Head-Driven Phrase Structure Grammar (HPSG)

HPSG is a well-developed, precisely formalized theory of grammar whose architecture is based on the notion of constraint satisfaction. Linguistic objects are modeled as feature structures organized via a system of types and constraint inheritance, drawing key insights from research in object-oriented paradigms. The HPSG community values explicit, large-scale grammar development and explores psycholinguistic models, as well as the development of efficient computational systems for processing natural languages using HPSG grammars. The following resources contain more information about some of these activities:

• The Stanford (CSLI) HPSG page
• The Ohio State HPSG page
• Interactive HPSG Bibliography (University of Bremen)
• Online Proceedings for the Int. HPSG Conferences since 2000
• The University of Tübingen HPSG page
• The DELPH-IN Collaboration. An international consortium devoted to combining HPSG grammars and statistical processing methods for `deep' processing of natural languages.
• CoGETI: Constraint-based Grammar: Data, Theory, and Implementation
  (research network involving five sites in Germany, and OSU)
• The HPSG Dialogue Project, King's College, London