MRS modeling mini-symposium at UW 2013-02-27



Topic: More clarity for named entities; how to annotate named entities in a corpus in a way that is useful.


ERG constraints:

Other questions:

NER in question is a set of tokenization rules which are part of the grammar; non-deterministic, doesn't disambiguate. Can also take external NERs which give labeled bracketing and have the parser respect those bracketed structures. Very useful for "The Wall Street Journal" and "The New York Stock Exchange".

List of cases to try to boil down to fewer rules. Target: What is the annotation handbook going to say to promote annotation consistency (and useful results)?

Candidate analyses:

External NER

Would be useful to have NE types as well as just NE/not NE. Compositional approach might also help with this.

Woodley: What about a separate external post-processor that tags named-entities with the benefit of the syntactic information? This span, btw, with this characteristic variable, is a named entity (of this type). Keeping all of the semantics of "the University of Washington" in there, and then add the named entity semantics as a separate way of addressing it.

Dan: Maybe based on the idiom processing… But there are reasons to not delay:

Today General Peripherals is announcing… The only way to get a singular verb is to make that one singular. So this needs to be done during parsing, in order to get the parse.

Emily: Could have a non-branching rule that makes the number change and puts in a named_entity rel.

Zina: What about coreference --- might refer back to something inside the named entity.

Dan: Also: the Universities of Washington and Oregon, the original University of Washington

What's the difference semantically? A named entity is anchored in a particular individual; common nouns name a set of individuals. Encoded in MRS with named_rel (distinctive predicate) plus associated quantifier (proper_q_rel).

Woodley: What's the object to a semantic representation that had both dog_rel and named_rel. Example?

Dan: Famous transformational grammarian Noam Chomsky

Zina: But that's only if the class is named in the surface string. But if you had a gazetteer that says what type of named entity each is, could that make it into the MRS?

Dan: In a general case, a referential index should be associated both with its class and its name.

Woodley: Fido chased the cat. String doesn't say what kind of entity Fido is, then get: generic_entity(x) and named_entity(x,CARG: Fido)

Zina: Propagating info about what kind of entity Fido is from other sources (e.g., context) and unify it in…

Dan: Not just convenient, but also gets at something deep about NPs. They can pick out a set of individuals (and maybe there might be none: no dog) or name a particular individual or in some cases name a class and pick out an individual.

Woodley: Put the CARG on the quantifier?

Dan: One relation with two attributes: CARG (name) and type/class attribute.

Emily: One argument against CARG is the attempt to try to get down to just one quantifier for the whole named entity in John Smith Jones --- need CARG (or equivalent) for each piece of that.

Mike: CARG feature with structured information inside of it?

Dan: EP that comes from University will contribute partial information about the predication --- fill in CARG or TYPE or both.

Emily: Relationship between TYPE and PRED?

Dan: They're different. For all nouns (in this hypothesis): PRED is noun_rel and then there's TYPE and PRED.

Mike [channeling Francis]: Position for link to WordNet or similar?

Dan: Almost certainly stick to something fairly close to stem form.

Dan: Already don't introduce separate PRED for distinct proper names --- it's always named_rel. Not a different kind to say we're going to do that for common nouns as well.

Emily: Seems very different to me. The relationship between a proper name and the individual named is different from the relationship between common nouns and the class of entities they describe. Propose instead: named_rel to wrap around transparent named entities, with underspecified CARG; could be filled in with post-processing.

Megan: What about song titles and movie titles? Mr. and Mrs. Smith

Dan: WSJ example: Your October 6th editorial So Long LA When safely bounded within double quotes, kind of tractable. But when only marked by capitalization, hard.

Woodley: The only reasonable way to handle these is with a preprocessing step that flags these for you. But that's not the same as using the preprocessor for everything.

Zina: Can still have a preprocessor for NEs and still look inside them.

Dan: First version of this will be in 1212 release of the ERG.

Woodley: Would be nice to normalize in post-processing so both types look the same in the output. (Plus flag saying who's responsible for guessing them.)

Dan: Would named entity grouping rule also apply to John Smith?

Emily: Yes, ideally.

Dan: What about John and Mary Smith ((John and Mary) Smith) and (John and (Mary Smith)) -- real ambiguity, but where does the proper_q introducing rule apply in the left-hand case?

Emily: Left-headed analysis of ((John and Mary) Smith)?

Dan: Yes, has to be.

Emily: So quantifier points to coordinated entity.

Dan: How do interpret that quantifier? What work is the proper_q doing? Seems like it's something about info about what to look for in the model. And if there's just one for John and Mary doesn't that mean you can only go look for the group John and Mary and wouldn't you want to find just John in addition?

Emily/Woodley: Two cats fought. That's just one quantifier, for multiple individuals.

Dan: proper_q is not any quantifier, it's a hunting license.

[... tennis match ...]

There may be consequences about whether we do the wrapping early or late in the case of multi-name named entities.

Woodley: General Electric announced a new car. The president made the announcement. Isn't that pointing back to part of the larger entity?

Dan: Not convinced that that's the same.

Dan: More generally, like the packaging idea, and leaving to post processing the question of whether to preserve the house or voice ness of the House or Voice of America.

Zina: Put in info about type?

Dan: Don't want the ambiguity that comes with Pacific_ocean and Pacific_company

Zina: Preprocessor could tell you?

Dan: Is it infallible?

Zina: Value of that attribute is a ranked list of possible classes. Still just one entry.

Prescott: That gets fragile; mixing in stuff the grammar doesn't care about. (The grammar doesn't have constraints that would interpret it.) Just a decoration.

Zina: But we have other kinds of decorations.

Emily: Could come in afterwards if it's a decoration. Doesn't have to come in before parsing.

Woodley/Prescott: Might be easier to do later on, with the info from the MRS.

As we were wrapping up: Discussion of how the "wrapper" rule might help solve the problem of post-modified nominal projections in the pre-head position of compounds: a University of Washington professor If the "wrapper" rule doesn't copy up the information about the post-modification/complementation when creating the named entity phrase, it could make these systematically eligible for that position, on the named entity reading.

RmrsNes (last edited 2013-02-28 02:06:19 by EmilyBender)

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