Question Answering via Question-to-Question Mapping

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Question Answering via Question-to-Question
Mapping

• Tait Larson
• Johnson Gong
• Josh Daniel

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Overview

• QA systems on the web currently are popular
• Common QA systems extract facts from the web,
  match natural language questions to facts
• Our approach
• Take pre-answered questions, and match questions
  to questions
• Hopefully useful because of the vast amount of
  pre-answered questions available on the web
• Google answers
• Yahoo answers
• Lawguru.com
• FAQs
• Do this via several NLP techniques, primarily
  focused around query expansion using Wordnet and
  language model

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Query Expansion

• POS tagging preprocess
• Search through domain of semantically similar
  sentences
• Goal Generate phrases that will identify
  semantically equivalent questions in our corpus
• Semantic expansion
• Language Model for pruning
• Prune incorrect word sense
• Trained on question repository
• Can I get into Stanford? -gt Butt I get into
  Stanford?
• Phrase Extraction

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Information Retrieval

• Different from traditional IR
• Bigrams
• Index
• Query
• No stop words
• No stemming
• Why?
• These choice emphasize semantic structure of
  question

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Results

• Us vs Yahoo
• Test questions from unresolved Yahoo questions
• Metric - Mean Reciprocal Rank
• We only index questions, Yahoo indexes answers
  also

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Example Results

• A sharp pain in the center of the chest
  breastbone area?
• Keep getting a throbbing pain in the middle of my
  rib cage . any idea what it could be?
• Do Bush baked beans give you gas
• Do baked beans make you fart???? yes/no?
• Why i sweat and how can i stop this problem
• How can I stop sweating? I sweat more when its
  cold

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