Problem Set 6

Assigned: Nov. 17
Due: Dec. 3.

Note: This is due in TWO weeks. If you are submitting this by email, please send it to Ernie Davis, davise@cs.nyu.edu, not to the TA.

Problem 1

Explain how each of the ambiguities specified below can be resolved by selectional restrictions. Your explanation should specify what are the constraints and the features involved.

For example: The lexical ambiguity of the word "bat" in the sentence, "The sick bat lay on the ground," (wooden club vs. flying mammal) is resolved by the constraint "If X is sick, then X must have the feature ANIMATE" and that facts that the meaning "club" does not have the feature ANIMATE whereas the meaning "mammal" does have the feature ANIMATE.

The anaphoric ambiguity of the word "it" in the sentence, "John sat down at his desk with a bagel and started to eat it" ("it"=bagel vs. "it"=desk) is resolved by the constraint "The object of eating must have the feature "EDIBLE", and the fact that "desk" does not have the feature "EDIBLE" but that "bagel" does have the feature "EDIBLE".

The syntactic ambiguity of "The man from Cincinatti with the red beard sang `Clementine'" (Does "with the red beard" modify "band" or "Cincinatti"?) is resolved by the constraint that the owner of a body part (beard) must have the feature ANIMATE, a man has the feature ANIMATE, but a city does not.

Problem 2

Explain how each of the ambiguities specified below can be resolved using selectional restrictions or world knowledge. You should be as precise as possible about what facts are being applied.