Conceptual Dependency

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Conceptual Dependency

• CIS 479/579
• Bruce R. Maxim
• UM-Dearborn

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What is it?

• Theory of how to represent the meaning of natural
  language sentences in a manner that
• facilitates drawing inferences from sentences
• is independent of the language in which the
  sentences were originally written

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CD

• Sentence representations are not built out of
  primitives that correspond to the words used
• Sentence representations are built out of
  conceptual primitives that can be combined to
  form meanings of words from a particular language

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Example

• To represent the sentence
• I gave the man a book.

R
p
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Example

• ATRANS Abstract transfer (e.g. give)
• PTRANS Physical transfer (e.g. go)
• MTRANS Mental transfer (e.g. tell)
• ? Arrow indicates direction of transfer
• ? Double arrow indicates two-way relationship
• p Past tense
• o Object case relation
• R Recipient case relation

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Example

• Conceptual categories
• Act Action
• PP object or picture producer
• AA Action modifier or aide
• PA Picture modifier or aider

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CD

• The sentence dependency structures are building
  blocks that can be used in larger dependency
  structures (e.g. paragraphs or scripts)
• The dependencies correspond to semantic relations
  among the underlying concepts

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How does CD facilitate reasoning with knowledge?

• Fewer inference rules are required than if
  knowledge is not broken down into primitives
• Many inferences are contained in the CD
  representation itself
• The initial representation built for a sentence
  may have holes in it and these holes serve to
  focus the programs attention as it tries to
  understanding the sentence meaning

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Arguments Against CD

• It takes a long time to decompose knowledge into
  low level primitives
• CD is a theory for representing events, so it may
  not do a good job of representing other types of
  knowledge (e.g. objects or social actions)