josef ruppenhofer, swapna somasundaran, janyce wiebe university of pittsburgh finding the sources...

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Josef Ruppenhofer, Swapna Somasundaran, Janyce Wiebe

University of Pittsburgh

Finding the sources and targets of subjective expressions

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What is Subjectivity?

• The linguistic expression of somebody’s opinions, sentiments, emotions, evaluations, beliefs, speculations (private states)

• This pleased the mainly female audience.Source: the person who experiences a private

stateTarget: what the private state is about or directed

towards

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MotivationSentiment analysis is a fast-growing field with

many applications (e.g. Question Answering, Product review mining, Information Extraction)

In many kinds of texts we find opinions attributed to several different sources, and/or opinions about multiple targets

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Opinion Question Answering

Q: What is the international reaction to the reelection of Robert Mugabe as President of Zimbabwe?

A: African observers generally approved of his victory while Western Governments strongly denounced it.

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Product review miningThe computer is very good and very easy to use. It has a built in camera, bluetooth; the all singing and dancing machine. Love it. The only glitch is the scrolling pad is not as smooth as my last Toshiba notebook. One other thing is that Vista is a nightmare...

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MotivationSentiment analysis is a fast-growing field with

many applications (e.g. Question Answering, Product review mining, Information Extraction)

In many kinds of texts we find opinions attributed to several different sources, and/or opinions about multiple targets

Challenge is to associate sources, opinions, and targets correctly

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RoadmapHere we discuss some of the challenges that

an automatic system needs to be able to deal with

We take the use of Automatic Semantic Role Labeling (ASRL) systems as our starting point

Based on our work in corpus annotation, we show that we need additional capabilities beyond ASRL

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Automatic Semantic Role Labeling

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Semantic roles

This pleased the mainly female audience.

PropBank FrameNet

Arg0 Experiencer

Arg1 Content

PropBank FrameNet

Arg1 Experiencer

Arg0 Stimulus

We fear an early death much more.

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Mapping opinion roles to semantic roles

This pleased the mainly female audience.

Opinion roles PropBank FrameNet

Source Arg0 Experiencer

Target Arg1 Content

Opinion roles PropBank FrameNet

Source Arg1 Experiencer

Target Arg0 Stimulus

We fear an early death much more.

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Annotation scheme

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Private states (Quirk et al. 1985)- States such as emotions, evaluations,

speculations, etc. - States that are not open to objective

observation or verification. - States that involve a particular person’s point

of view- Private states involve sources holding

attitudes, typically towards targets.

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Ways of evoking private statesExplicit mentions:

He was boiling with anger.Speaking events expressing private states:

The paper’s editors attacked the new House Speaker.

Expressive subjective elements (Banfield 1982):That doctor is a quack.

Objective speech events:“The bus leaves at 4”, Bill said.

DSEs

ESEs

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Nesting of private states

``The US fears a spill-over,” said Xirao-Nima.

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Nesting of private states

``The US fears a spill-over,” said Xirao-Nima.

The US fears a spill-over

“ “ said Xirao-Nima

<writer>

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Challenges beyond role labeling

Sources Targets

Attribution

Referent Identification

Inferences

Arguing Attitudes

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Attribution

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AttributionExpressive subjective elements (ESEs) don’t have a semantic role for their source:

Senior Mike Sheehy said , “It was a blast ”.

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AttributionThe source for an ESE is not always at the same level. Compare:

Senior Mike Sheehy said, “It was a blast”.

She loves that idiot.

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Senior Mike Sheey said, “It was a blast”

<writer> <writer>

She loves that idiot.

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AttributionSome expressions function both as ESEs and as DSEs:

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AttributionSome expressions function both as ESEs and as DSEs:

It is a shame that there is no jury that can mete out justice for a city he has slandered for far too long.

source target

DSE He city

ESE <writer> he

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AttributionAttribution and content of a private state may be presented separately:

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AttributionAttribution and content of a private state may be presented separately:

Chris Moyles is a brilliant broadcaster, the saviour of Radio 1, a comedian, a best-selling author, and, in fact, a genius. Or so he says.

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Attribution

Chris Moyles is a brilliant broadcaster, the saviour of Radio 1, a comedian, a best-selling author, and, in fact, a genius.

<writer>

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Attribution

Chris Moyles is a brilliant broadcaster, the saviour of Radio 1, a comedian, a best-selling author, and, in fact, a genius.

<writer>

<Chris Moyles>

Or so he says

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AttributionAn attribution may apply to several utterances without being explicitly signaled each time.

And I went ahead and mailed it in

thinking uh I won’t get the scholarship.Who cares?I don’t, just so I can work in the school and I’ll be happy.

But one day I came in and I looked at my mail and I was accepted.

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Inferences

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InferencesFor some events about which opinions are expressed, we can infer additional attitudes towards affected or causing participants:

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InferencesFor some events about which opinions are expressed, we can infer additional attitudes towards affected or causing participants:

I think people are happy because Chavez has fallen.

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InferencesFor some events about which opinions are expressed, we can infer additional attitudes towards affected or causing participants:

I think people are happy because Chavez has fallen.

I think people are happy because Chavez has fallen.

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Targets of arguing

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Arguing attitudes1. What is the case or not

From this it follows that mechanisation is not economic unless it can produce higher yields of crops than these older methods.

2. What should be done or not

We strongly recommend that all Firefox users upgrade to this latest release.

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Targets of arguing Interpretation of arguments made by causal

and conditional constructions is very context-dependent.

Your presentation will be better [if you put this on the first slide]

You will want to vote YES [if you want to keep the cost of government in Lewiston low]

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Targets of arguing Interpretation of arguments made by causal

and conditional constructions is very context-dependent.

Hypothetical: Your presentation will be better [if you put this on the first slide]

Implicit assertion You will want to vote YES [if you want to keep the cost of government in Lewiston low]

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Targets of arguing• The prototypical targets that we annotate are

entities. • For arguing, we could also annotate the entities

that arguments are about.• However, we also recognize that the logical

targets of arguing are propositions.

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Targets of arguing• Clinton should be the presidential candidate.

Clinton should be the running mate.

• The prototypical targets that we annotate are entities.

• For arguing, we could also annotate the entities that arguments are about.

• However, we also recognize that the logical targets of arguing are propositions.

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Targets of arguing• Clinton should be the presidential candidate.

Clinton should be the running mate.

• The prototypical targets that we annotate are entities.

• For arguing, we could also annotate the entities that arguments are about.

• However, we also recognize that the logical targets of arguing are propositions.

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Targets of arguing• Clinton should be the presidential candidate.

Clinton should be the running mate.

• The prototypical targets that we annotate are entities.

• For arguing, we could also annotate the entities that arguments are about.

• However, we also recognize that the logical targets of arguing are propositions.

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Targets of arguing• Clinton should be the presidential candidate.

Clinton should be the running mate.

• The prototypical targets that we annotate are entities.

• For arguing, we could also annotate the entities that arguments are about.

• However, we also recognize that the logical targets of arguing are propositions.

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ConclusionSemantic role labeling is needed for finding

sources and targets

But we also needways of establishing levels of attributioncapabilities for dealing with zero referenceslexical information to support inferencesdeal with the full variety of attitudes and their

sources and targets

Thanks!

josefr@cs.pitt.edu

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References: Annotation schemeBanfield, Ann. 1982. Unspeakable Sentences:

Narration and Representation in the Language of Fiction. Routledge & Kegan Paul, Boston.

Quirk Randolph, Greenbaum Sidney, Leech Geoffrey, and Svartvik Jan. 1985. A Comprehensive Grammar of the English Language. Longman, New York, NY.

Janyce Wiebe M. 1994. Tracking point of view in narrative. Computational Linguistics 20 (2): 233-287.

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References: Annotation schemeJanyce Wiebe, Theresa Wilson , and Claire Cardie.

2005. Annotating expressions of opinions and emotions in language. Language Resources and Evaluation, volume 39, issue 2-3, pp. 165-210.

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References: Role LabelingPenn Discourse Treebank

http://www.seas.upenn.edu/~pdtb/PDTBAPI/pdtb-annotation-manual.pdf

PropBankhttp://verbs.colorado.edu/~mpalmer/projects/ace.html

FrameNethttp://framenet.icsi.berkeley.edu/

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References: Role LabelingY. Choi, E. Breck, and C. Cardie. 2006. Joint

Extraction of Entities and Relations for Opinion Recognition. In Proc. of EMNLP 2006.

S. Kim and E. Hovy. 2006. Extracting Opinions, Opinion Holders, and Topics Expressed in Online News Media Text. In ACL Workshop on Sentiment and Subjectivity in Text.

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References: Belief spacesDyer, Michael G. 1983. In-Depth Understanding: A

Computer Model of Integrated Processing for Narrative Comprehension. MIT Press, Cambridge, MA.

Fauconnier, Gilles. 1985. Mental Spaces: Aspects of Meaning Construction in Natural Language. MIT Press, Cambridge, MA.

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References: Belief spacesRapaport, William J. 1986. Logical Foundations for

Belief Representation. Cognitive Science.Wilks, Yorick and Bien, Janusz. Beliefs, Points of

View, and Multiple Environments. Cognitive Science 7: 95-119.

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References: Literary theoryChatman, Seymour. 1978. Story and Discourse:

Narrative Structure in Fiction and Film. Cornell University Press, Ithaca, NY.

Cohn, Dorrit. 1978. Transparent Minds: Narrative Modes for Representing Consciousness in Fiction Princeton University Press, Princeton, NJ.

Dolezel, Lubomir. 1973 .Narrative Modes in Czech Literature. University of Toronto Press, Toronto, Canada.

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References: Literary theoryHamburger Käte. 1973. M.J. Rose, Trans., The Logic

of Literature. Indiana University Press, Bloomington, Indiana.

Kuroda, S.-Y. 1976. Reflections on the Foundations of Narrative Theory--From a Linguistic Point of View. In: van Dijk, T.A., Ed., Pragmatics of Language and Literature, North Holland, Amsterdam.

Uspensky, Boris. 1973. A Poetics of Composition. University of California Press, Berkeley, CA.

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References: DiscourseAllen, James F. and Perrault, C. Raymond. 1980.

Analyzing Intention in Utterances. Artificial Intelligence 15: 143-178.

Fillmore, Charles. 1974. Pragmatics and the Description of Discourse. In: Fillmore, Charles, Lakoff, George, and Lakoff, Robin, Eds., Berkeley Studies in Syntax and Semantics I. University of California Dept. of Linguistics and Institute of Human Learning, Berkeley, CA: V1-V21.