PowerPoint Presentation "NaturalLanguageUnderstanding"

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Adapted from Communication and Language , by
Faisal Alkhateeb. Yarmouk University Linguists
have defined different levels of analysis for
natural language
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Difficulty in understanding natural
languages (Ambiguity)

• Natural languages are inherently ambiguous.
• Types of ambiguity
• Structural ambiguity
• Lexical ambiguity
• Scope ambiguity
• referential ambiguity

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Difficulty in understanding natural languages

• 1. Structural ambiguity
• A string can be associated with more than one
  structure (or parse trees).
• Examples - dangling else in programming
  languages
• - The string ab can be derived in many ways
• S ? A B
• A ? aAb ab
• B ? abB A

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Difficulty in understanding natural languages

• 2. Lexical ambiguity
• A word can be associated with more than one part
  of speech (word class) or more than one sense.
• Examples - net net salary. A net of computers.
• - Calm ? verb or noun

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Difficulty in understanding natural languages

• 3. Scope ambiguity
• A type of semantic ambiguity where the same
  structures and word senses can still have
  multiple interpretations.
• Not operates on the meaning of other words and
  structures and may produce scope ambiguity.
• Examples - I did not give you a lot of
  chocolates.
• - I did not drive the car to the university.
  (stay at home or I drove elsewhere)

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Difficulty in understanding natural languages

• 4. Referential ambiguity
• A type of semantic ambiguity where the same
  structures and word senses can still have
  multiple interpretations.
• A word or a structure can be referred to more
  than one interpretation.
• Examples - I have a visit to Aqaba through
  Petra, it was so beautiful.
• David decided to hide the keys of Freds car
  because he ...
• didnt want him to drive.
• was joking with him.
• had had too much to drink.

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