24,646 research outputs found
Query-Based Summarization using Rhetorical Structure Theory
Research on Question Answering is focused mainly on classifying the question type and finding
the answer. Presenting the answer in a way that suits the userâs needs has received little
attention. This paper shows how existing question answering systemsâwhich aim at finding
precise answers to questionsâcan be improved by exploiting summarization techniques to extract
more than just the answer from the document in which the answer resides. This is done
using a graph search algorithm which searches for relevant sentences in the discourse structure,
which is represented as a graph. The Rhetorical Structure Theory (RST) is used to create a
graph representation of a text document. The output is an extensive answer, which not only
answers the question, but also gives the user an opportunity to assess the accuracy of the answer
(is this what I am looking for?), and to find additional information that is related to the question,
and which may satisfy an information need. This has been implemented in a working multimodal
question answering system where it operates with two independently developed question
answering modules
Hypotheses, evidence and relationships: The HypER approach for representing scientific knowledge claims
Biological knowledge is increasingly represented as a collection of (entity-relationship-entity) triplets. These are queried, mined, appended to papers, and published. However, this representation ignores the argumentation contained within a paper and the relationships between hypotheses, claims and evidence put forth in the article. In this paper, we propose an alternate view of the research article as a network of 'hypotheses and evidence'. Our knowledge representation focuses on scientific discourse as a rhetorical activity, which leads to a different direction in the development of tools and processes for modeling this discourse. We propose to extract knowledge from the article to allow the construction of a system where a specific scientific claim is connected, through trails of meaningful relationships, to experimental evidence. We discuss some current efforts and future plans in this area
Algorithms for Analysing the Temporal Structure of Discourse
We describe a method for analysing the temporal structure of a discourse
which takes into account the effects of tense, aspect, temporal adverbials and
rhetorical structure and which minimises unnecessary ambiguity in the temporal
structure. It is part of a discourse grammar implemented in Carpenter's ALE
formalism. The method for building up the temporal structure of the discourse
combines constraints and preferences: we use constraints to reduce the number
of possible structures, exploiting the HPSG type hierarchy and unification for
this purpose; and we apply preferences to choose between the remaining options
using a temporal centering mechanism. We end by recommending that an
underspecified representation of the structure using these techniques be used
to avoid generating the temporal/rhetorical structure until higher-level
information can be used to disambiguate.Comment: EACL '95, 8 pages, 1 eps picture, tar-ed, compressed, uuencoded, uses
eaclap.sty, a4wide.sty, epsf.te
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