Homework: Ambiguity and Semantic Processing

Exercises

• Selectional Restrictions
  1. Select two ambiguous verbs, and describe their different meanings.
  2. Write example sentences for each verb.
  3. Show how selectional restrictions could be used to disambiguate the sentences.

• Semantic Roles
  1. Indicate the semantic roles for each noun phrase in these sentences:

        "John sprayed the wall with paint."
        "The wall was sprayed with paint."
        "John finished the pizza with Bill."
        "The vase broke."
     

  2. Write one or more sentences which illustrate these semantic roles; mark each noun phrase with its role (see Allen, Figure 8.6): FROM-LOC, TO-POSS, TO-LOC, AT-LOC, BENEFICIARY, EXPERIENCER

• Semantic Grammars

  Use the semantic grammar given in Section 15.3.1 of the Rich and Knight handout to parse the following sentences. Draw parse trees like the one shown in Figure 15.11, and be sure to provide both the phrase structure tree and the semantic annotations for the frame representation that is built at each node in the tree. Assume this extra rule, which is omitted by Knight and Rich:

     PRINTER --> shakthi 
                 {value}
  

  1. "What is protection of Bob's .ps file?"

  2. "I want to print Bill's .init file on shakthi."

Background Material

/afs/cs/project/cmt-55/lti/Courses/711/html/index.html