HOMEWORK 5

In this homework, we'll consider the Automatic Content Extraction (ACE) task, which involves the automatic extraction of entities and the relationships between them. Examples include determining locations of cities, leaders of organizations, and members of political parties.

The following documents may help to familiarize you with the ACE task:

• a sample text
• sample entity/relation annotations for the same text
  • (If your browser doesn't render this XML file in raw form, it might be better to download it and view it in a text editor.)
• the annotation guidelines for the ACE relation detection and characterization task

Now, in English, the possessive construction can signal a broad variety of relations. Consider these examples:

1. [Fox News Channel's] [Mort Kondracke] called it "an opportunity wasted by Cheney to go after Gore."
2. [The National Action Party's] [Vicente Fox] will be sworn in as president Dec. 1.
3. Ten Senate seats were awarded to candidates of [Aristide's] [Lavalas party] through a vote counting method later discredited by the international community.
4. 6 Die in [Indonesia's] [Aceh Province]
5. Arafat also knows that [Iraq's] [Saddam Hussein], developing weaponry to counter Israel's nuclear deterrent, is spoiling to send his tanks and Scuds through Jordan into his enemy's homeland.
6. The US Supreme Court will hear arguments from both sides on Friday and [Florida's] [Leon County Circuit Court] will consider the arguments on disputed state ballots on Saturday.

Now some questions:

1. [3 points] For each of the examples above, identify the appropriate ACE type and subtype of the relation between the two entities in brackets. The possible relation types and subtypes are enumerated and described in section 2 of the annotation guidelines. (For example, the first relation type listed in the annotation guidelines is PHYS; the first relation subtype listed is Located.)
2. [3 points] The assigned reading for today, Zhou et al. 2005, identified one feature in their system which yielded the largest gains in recall. What is that feature, and what is its value for each of the examples above? Can you offer a (brief) interpretation as to why this feature might be so helpful?
3. [2 points] The above examples illustrate just a few of the many semantic relations which can be expressed by the possessive. Provide an English sentence that illustrates a relation not represented in these examples, and identify its ACE type and subtype.
4. [2 points] What cues might a relation extraction system use to distinguish among the variety of relations commonly expressed by the possessive construction?