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Event-Centric Summary Generation. Lucy Vanderwende, Michele Banko and Arul Menezes One Microsoft Way, WA, USA DUC 2004. Abstract. Our primary interest is two folds: To explore an event-centric approach to summarization To explore a generation approach to summary realization. - PowerPoint PPT Presentation
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Event-Centric Summary Generation
Lucy Vanderwende, Michele Banko and Arul Menezes
One Microsoft Way, WA, USA DUC 2004
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Abstract
• Our primary interest is two folds:– To explore an event-centric approach to
summarization– To explore a generation approach to summary
realization
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Introduction
• Identifying important events, as opposed to entities
• Generation component– Human-authored rely less on sentence
extraction
• Graph-scoring algorithm– To identify highest weighted node to guide
content selection
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System Description
• MSR-NLP– Analysis component
• Rule-base syntactic analysis component• Produces a logical form
– Syntactic variations, words label
– Generation component• Syntactic realization component• Produces a syntactic tree
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Creating document representations
• Cluster sentence
• Analysis sentence and get logical form
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Creating document representations
• Produces triples result from logical form– (LFNodei, rel, LFNodej)
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Forming Document Graph
• Take those triples and join nodes by way of their semantic relation using a bidirectional link structure
• Keep track of how many times we observe the relationship
• Stop words are not included in the graph construction
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Node scoring Using Pagerank
• Using Pagerank algorithm– Hyperlink such as WWW– When link between nodes, vote for that node
–
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Node scoring Using Pagerank
• Pagerank framework– “Pages”, correspond to base forms of words in the do
cuments– “hyperlink”, correspond to semantic relationships– Verbs, identify events– Noun, Identify entities– Use event to identify summary content
• Typically, the algorithm converges around 40 iterations
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Graph Scoring
• Use pagerank scores to assess the link weight (LW(i->n))
•
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Summary Generation
• Generated by extracting and merging of logical form– Identify important triples
• Defined highly link weight node, and together with most highly weighted
• (leave, Tobj, LonLondon_Bridge_Hospital)• Not (leave, Tobj, government)
– Extract fragments divided into “event” and “entity”
• Event used to generate summary• Entity used to expanded upon reference to the sa
me entity within the selected event fragment
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Summary Generation
• Event fragment order– Cluster event fragment by they refer to – Choose the greatest number of argument nod
e for the event– Order the selected event fragments
• To group sentence referring to the same entity together
• Order sentence which exhibit event-coreference
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Experiments and Evaluation
•
(Rule-based pronoun resolution method, 75% accuracy)
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Experiments and Evaluation
•
Reason: the potential to introduce disfluent text
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Directions and Future Work
• Produce more human-like generated summaries
• Further study the impact of anaphora resolution
• Study new page-ranking algorithm• While ordering groups event fragments
mentioning the same entity, we have not yet implemented a system to combine them into larger logical form construction
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