Experiments in reusability of grammatical resources

Abstract

Substantial formal grammatical and lexical resources exist in various NLP systems and in the form of textbook specifications. In the present paper we report on experimental results obtained in manual, semi-antomatic and automatic migration of entire computational or textbook descriptions (as opposed to a more informal reuse of ideas or the design of a single "poly-theoretic" representation) from a variety of formalisms into the ALEP formalism. 1 The choice of ALEP (a comparatively lean, typed feature structure formalism based on rewrite rules) was motivated by the assumption that the study would be most interesting if the target formalism is relatively mainstream without overt ideological commitments to particular grammatical theories. As regards the source formalisms we have attempted migrations of descriptions in HPSG (which uses fully-typed feature structures and has a strong 'non-derivational' flavour), ETS (an untyped stratificational formalism which essentially uses rewrite rules for feature structures and has run-time non-monotonic devices) and LFG (which is an un-typed constraint and CF-PSG based formalism with extensions such as existential, negative and global well-formedness constraints).