CS413 Artificial Intelligence
Winter 2002-2003
Homework 3: Knowledge-Based Natural Language Processing
John Paul Taylor II

1. Using conceptual dependency:

  1. Sally drove a motorcycle to New York.
      (ptrans
       (actor (person (name (sally))))
       (object (person (name (sally))))
       (object (motorcycle))
       (to (city (name (new york)))))
  2. John donated his sofa to the Salvation Army.
      (atrans
       (actor (person (name (john))))
       (object (sofa))
       (from (person (name (john))))
       (to (Salvation army)))
  3. John roared into town in a new BMW.
      (ptrans
       (actor (person (name (john))))
       (object (BMW))
       (object (person (name (john))))
       (to (town)))
  4. John ate popcorn with his foot.
      (ingest
       (actor (person (name (john))))
       (object (popcorn))
       (with (foot)))
  5. Mary broke John's TV.
      (break
       (actor (person (name (mary))))
       (object (tv (owner (person (name (john)))))))

4. Ambiguity of words:

In general, ambiguous nouns are recognized in the English language by context. In this case the feasible context to look at is that of the current sentence. For “Bill paid the bill,&rdquo the context of “the bill” implies that we aren't refering to a name. Capitalization can also be inmportant. Unfortunately, we often must make guesses to clarify ambiguity.

In the scope of MicroELI, the framework would have to be changed to include such english ideas as direct objects, proper nouns, prepositions, and other parts of speech. Requests would natural have to keep this in mind. For example, ‘bill’ as a direct object is likely to represent an invoice, while ‘bill’ in the preposition ‘with’ is likely to represent paper money.

5. Difficulty of CD:

Representing a sentence is relatively easy when it is a simple statement of a basic fact in the standard noun-verb-noun sentence structure. Examples include “Blorg is a frood,” and “The toves gyred in the wabe.” Difficulty arises when the sentence structure is varied or the ideas presented are not easily represented. These include “To his house went Jack,” and “The department justified its existence based on the obvious knowledge that it existed.”