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Lecture 19: Question Answering
Kai-Wei ChangCS @ University of Virginia
kw@kwchang.net
Couse webpage: http://kwchang.net/teaching/NLP16
1CS6501-NLP
Question answering
CS6501– Natural Language Processing 2credit:ifunny.com
'Watson' computer wins at 'Jeopardy'
Question answering
vGo beyond search
CS6501– Natural Language Processing 3
Go beyond traditional web search
Answer queries using structured knowledge
vGoogle Knowledge GraphvFacebook Graph SearchvBing’s Satori
Need to understand the query!
CS6501-NLP 4
Thefollowing slidesaremodified fromChristopherManning&Pandu Nayak’s intro.toIR.
ExamplefromFernandoPereira(GOOG)
Paradigms for question answering
vText-based approachesvTREC QA, IBM Watson
vStructured knowledge-based approachesvApple Siri, Wolfram Alpha, Facebook Graph
Search
CS6501-NLP 12
Task – Answer Sentence Selection
v Given a factoid question, find the sentence that v Contains the answerv Can sufficiently support the answer
Q: Who won the best actor Oscar in 1973?S1: Jack Lemmon was awarded the Best Actor Oscar for Save
the Tiger (1973).S2: Academy award winner Kevin Spacey said that Jack
Lemmon is remembered as always making time for others.
Scott Wen-tau Yih (ACL 2013) paper
Lemmon was awarded the Best Supporting Actor Oscar in 1956 for Mister Roberts (1955) and the Best Actor Oscar for Save the Tiger (1973), becoming the first actor to achieve this rare double…Source: Jack Lemmon -- Wikipedia
Who won the best actor Oscar in 1973?
AssumethatthereisanunderlyingalignmentDescribeswhichwordsinandcanbeassociated
What is the fastest car in the world?
The Jaguar XJ220 is the dearest, fastest and most sought after car on the planet.
Word Alignment for Question AnsweringTREC QA (1999-2005)
See if the (syntactic/semantic) relations support the answer
[Harabagiu & Moldovan, 2001]
Knowledge-based QA
vBuild a semantic representation of the queryvTimes, dates, locations, entities, numeric quantities
vMap from this semantics to query structured data or resourcesvDatabase vOntologies (Wikipedia infoboxes, dbPedia,
WordNet, Yago)vScientific databases
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Linking Open Data cloud Diagram
CS6501-NLP 17
http://lod-cloud.net/
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