I thought this paper was interesting. They argue that many cases in coreference resolution are more complicated than simple binary decisions, and so they introduce “near-identity” relations, somewhere in between saying two entities are coreferent and not coreferent. I thought they had some good examples, but in the end I found their typology not incredibly persuasive. I would have said most of them were not coreferent and dealt with the subtlety another way. I’ll give some of their examples below, with the entities that are coreferent or near-identity in italics.

Last night in Tel Aviv, Jews attacked a restaurant that employs Palestinians. “ We want war,” the crowd chanted.

The Clinton campaign is circulating a fake photo of Barack Obama in Muslim clothes to damage his reputation. In the photo, Obama wears a long sari-like garment.

The Clinton campaign is circulating a fake photo of Barack Obama in Muslim clothes to damage his reputation, but Obama never wore Muslim clothes.

The above two contrasting sentences are particularly interesting, because a simple analysis would have the two being actually coreferent in the first sentence, leading to the erroneous conclusion that Obama wore a long sari-like garment, when in fact he did not; the fake Obama did.

There are some other interesting examples in the paper where pronouns are used, which would make you think that the entities are coreferent, but in fact they are only near-identity. For example:

In France, the president is elected for a term of seven years, while in the United States he is elected for a term of four years.

Language is much more complicated than speakers tend to think it is, and it’s really hard to get all of these things right when a computer is processing the language. Studying linguistics in more depth the last few months has been really eye-opening for me.