Approximating an Interlingua in a Principled Way

We address the problem of constructing in a principled way an ontology of terms to be used in an interlingua for machine translation. Given our belief that the a true language-neutral ontology of terms can only be approached asymp-totically, the construction method outlined involves a step-wise folding in of one language at a time. This is effected in three steps: first building for each language a taxonomy of the linguistic generalizations required to analyze and generate that language, then organizing the domain entities in terms of that taxonomy, and finally merging the result with the existing interlingua ontology in a well-defined way. This methodology is based not on intuitive grounds about what is and is not 'true' about the world, which is a question of language-independence, but instead on practical concerns, namely what information the analysis and generation programs require in order to perform their tasks, a question of language-neutrality. After each merging is complete, the resulting taxonomy contains, declaratively and explicitly represented , those distinctions required to control the analysis and generation of the linguistic phenomena. The paper is based on current work of the PANGLOSS MT project. 1. Interlinguas This paper presents a method of constructing in a prin-cipled way an ontology of terms to be used as a source of terms in an interlingua for machine translation. The method involves taxonomizing relevant linguistic phenomena in each language and merging the resulting tax-onomy with the interlingua ontology to produce an on-tology that explicitly records the phenomena that must be handled by any parser or generator and is neutral with respect to the languages handled by the system. 1.1. What is an Interlingua? In interlingual machine translation, the representational power of the interlingua is central to the success of the translation. By interlingua we mean a notation used in MT systems to represent the propositional and pragmatic meaning of input texts; an interlingua text that represents the meaning of a source language text is produced by computational analysis, and is then used as input to a generation module which realizes this meaning in a target language text. An interlingua consists of the following three parts: a collection of terms: the elements that represent individual meanings (of lexical items, pragmatic aspects , etc.); this collection is organized in a multiply interconnected semantic network; notation: the syntax to which well-formed interlin-gua texts conform; substrate: the knowledge representation system in which interlingua …