From “hand-written ” to computationally implemented HPSG theories 1 Overview <s> Overview <s> We propose the creation of a web-based training framework comprising a set of topics that revolve around the use of feature structures as the core data structure in linguistic theory, its formal foundations, and its use in syntactic processing. <s> BIB001 </s> From “hand-written ” to computationally implemented HPSG theories 1 Overview <s> Overview <s> V erb -In itial C on stru ction s in M odern H ebrew by Nurit Melnik B.Sc. (The Hebrew University of Jerusalem) 1993 M.A. (University of California, Berkeley) 1999 A dissertation subm itted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Linguistics in the GRADUATE DIVISION of the UNIVERSITY OF CALIFORNIA, BERKELEY Committee in charge: Professor Andreas Kathol, Chair Professor Paul Kay Professor Johanna Nichols Fall 2002 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. <s> BIB002
HPSG has logical and mathematical foundations which make it amenable to computational implementation. Yet it is seldom the case that this potential is in fact fulfilled, although there exist a number of platforms for implementing HPSG grammars. Thus, most descriptions and analyses of linguistic phenomena in the literature are not substantiated by a working computational grammar. Two leading implementation platforms are available for implementing HPSG grammars. The Linguistic Knowledge Building (LKB) system  ) is the primary engineering environment of the LinGo English Resource Grammar (ERG) at Stanford. LKB is developed not particularly for implementing HPSG grammars, but rather, as a framework independent environment for typed feature structures grammar. TRALE, an extension of the Attribute Logic Engine (ALE) system, is a grammar implementation platform that was developed as part of the MiLCA project BIB001 , specifically for the implementation of theoretical HPSG grammars that were not explicitly written for language processing. 1 The two platforms are based on different approaches, distinct in their underlying logics and implementation details. This paper adopts the perspective of a computational linguist whose goal is to implement an HPSG * This research was supported by the Israel Science Foundation (grant no. 136/01) and by The Caesarea Edmond Benjamin de Rothschild Foundation Institute for Interdisciplinary Applications of Computer Science. 1 See http://milca.sfs.nphil.uni-tuebingen.de/A4/HomePage/ English/beschr.html theory. It is based on the implementation of a "handwritten" grammar proposed by BIB002 to account for verb initial constructions in Modern Hebrew. A representative subset of the grammar, including word order, agreement, and valence alternation phenomena, serves as a test case. The paper focuses on different dimensions, relevant to HPSG grammar implementation: type definition, grammar principles, lexical rules, exhaustive typing, definite relations, non-binary grammar rules, semantic representation, grammar evaluation, and user-interface. It examines, compares, and evaluates the different means which the two approaches provide for implementation, by referring to examples from a "hand-written" grammar fragment that was implemented in the two systems. The paper concludes that the approaches occupy diametrically opposed positions on two axes: FAITHFULNESS to the "hand-written' theory and COMPUTATIONAL AC-CESSIBILITY. The findings of this paper are valuable to linguists who are interested in implementing their grammar, as well as to those who develop implementation platforms.