Sentence Adverbials in a System of Question Answering Without a Prearranged Data Base

SENTENCE ADVERB I ALS IN A SYSTEM OF QUEST I ON ANSWER I NG W I THOUT A PREARRANGED DATA BASE Eva Kokt ova Hamburg, Wes t-Germany Abstract In the present paper we provide a report on a joint approach to the computational treatment of sentence adverbials (such as surprisingly, presumably or probably) and focussing adverbials (such as onl~ or a__ E least, including negation (not) and some other adverbial expressions, such as for examE_ ~ or inter alia) within a system of question answering without a prearranged data base (TIBAQ). This approach is based on a joint theoretical account of the expressions in question in the framework of a functional description of language; we argue that in the primary case, the expressions in question occupy, in the underlying topic- focus articulation of a sentence, the focus- initial position, extending their scope over the focus, or the new information, of a sentence, thus specifying, in a broad sense of the word, how the new information of a sentence holds. On the surface the expressions in question are usually moved to scope-ambiguous positions, which can be analyzed by means of several general strategies. 1. Introduction The present paper provides a report on the integration of sentence adverbials (such as surprisingly, presumabl~ or probably) and focussing adverbials (such as only or at least, including negation (not) and certain other adverbial expressions, such as for example or inter alia) into a system of question answering (factual information retrieval) without a prearranged data base, i.e. with a data base consisting only of input technical texts in natural langage (TIBAQ). (Throughout this paper, the expressions in question will be jointly referred to as CA expressions.) The presence of CA expressions in natural- language sentences (the functioning of these expressions being closely connected with the topic-focus articulation, or communicative perspective, of a sentence) is one of the outstanding features in which natural- languge-sentences differ from their corresponding logical formulas (or their equivalents in various knowledge- representation systems), marking the dynamic and pragmatically based character of verbal communication, in contradistinction to the static, inventory-like character of logical formulas. In the present paper we propose to treat CA-expressions on a joint syntactico- semantic account, namely in terms of a single adverbial complementation (Complementation of Attitude), by means of 68 which it is possible to economically account for all of the properties which they share from the viewpoint of the synthesis and analysis of sentences: essentially, we argue that the scope of CA expressions extends primarily over the focus, or the new information, of a sentence, and that CA expressions are usually moved on the surface to various scope-ambiguous positions, which can be disambiguated by several general strategies concerning the topic-focus articulation of a sentence (these strategies are used in the algorithm of analysis of CA expressions). The class of CA expressions is supposed to be open-ended, bat the majority of them can be listed. 2. Computational and Theoretical Background 2.1 Computational background. The experimental system of automatic question-answering …

Content truncated to 500 words