Micro-propositions as a basis for deep text understanding...Propositions can be decomposed...
Transcript of Micro-propositions as a basis for deep text understanding...Propositions can be decomposed...
Micro-propositions as a basis for deep textunderstanding
Chantal van Son, Lora Aroyo, Roser Morante, Piek Vossen
VU Amsterdam
December 15, 2017
Second International Symposium on Cross-disciplinary Research in the Health Humanities and Beyond:
Perspectives and Knowledge Landscapes in the Digital Health Society
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 1 / 25
Outline
Outline I
1 Introduction
2 Texts as collections of propositions
3 Perspectives: attribution & factuality
4 Micro-propositionsWhat are micro-propositions?Why do we need micro-propositions?
5 Future directions
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 2 / 25
Introduction
Outline
1 Introduction
2 Texts as collections of propositions
3 Perspectives: attribution & factuality
4 Micro-propositionsWhat are micro-propositions?Why do we need micro-propositions?
5 Future directions
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 3 / 25
Introduction
Introduction
Much medical and health-related information is found online in the formof text (unstructured data)
Large variety of sources with different backgrounds and motivations
Result: complex debate about what is true and what is not
Direct: explicit (dis)agreement with previously made statementsIndirect: distributing contradictory or affirmative statements
Difficult for citizens, researchers and medical professionals to obtain areasonable overview of existing beliefs
Today: examples from the vaccination debate
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 4 / 25
Introduction
Fast-forward: the goal
GOAL: Automatically extracting and comparing beliefs/statements fromtexts using Natural Language Processing
Mike Adams(NaturalNews)
VACCINES ARE INEFFECTIVE
VACCINES ARE TOXIC
VACCINES CAUSE DEATH
VACCINES ARE UNNECESSARY
ADVERSE REACTIONS ARE FREQUENT
VACCINES CAUSE AUTISM
VACCINES CAUSE OUTBREAKS
Centers for Disease Controland Prevention
VACCINES ARE EFFECTIVE
VACCINES ARE SAFE
VACCINES SAVE LIVES
VACCINES ARE NECESSARY
ADVERSE REACTIONS ARE RARE
VACCINES PREVENT ILLNESSES
LOW VACCINATION RATES CAUSE OUTBREAKS
+ attitude of source towards statement
+ relations between statements (and indirectly: between sources)
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 5 / 25
Introduction
Rewind: the reality
Mike Adams (NaturalNews)
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak thathealth authorities believe started at Disneyland, actual science suggests that themost likely cause of this insanely overblown outbreak was a person who was recentlyvaccinated. Numerous published studies reveal how live-virus vaccines like MMR(measles, mumps and rubella) actually shed these diseases for many weeks or evenmonths following vaccination, potentially infecting others, both vaccinated andunvaccinated. This means that any child who was recently given an MMR vaccineis a walking disease-spreader, a truth that the media is refusing to report as evenjust a possibility in this case.
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 6 / 25
Introduction
Rewind: the reality
Centers for Disease Control and Prevention
High population immunity secondary to high measles vaccination coverage hasmaintained measles elimination in the United States since declaration of eliminationin 2000 (5). Worldwide, however, approximately 20 million measles cases occurannually, and importations to the U.S. will continue to place unvaccinatedpopulations at risk for measles. Measles transmission in pockets of unvaccinatedpersons increases the risk for transmission to vulnerable groups, such as those whocannot be vaccinated because of underlying medical conditions, or infants tooyoung to be vaccinated.
Both texts are talking about the cause of measles outbreaks(vaccines/unvaccinated)
So how do we get from these complex and unstructured texts to conciseand understandable statements that we can reason over and compare?
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 7 / 25
Introduction
Rewind: the reality
Centers for Disease Control and Prevention
High population immunity secondary to high measles vaccination coverage hasmaintained measles elimination in the United States since declaration of eliminationin 2000 (5). Worldwide, however, approximately 20 million measles cases occurannually, and importations to the U.S. will continue to place unvaccinatedpopulations at risk for measles. Measles transmission in pockets of unvaccinatedpersons increases the risk for transmission to vulnerable groups, such as those whocannot be vaccinated because of underlying medical conditions, or infants tooyoung to be vaccinated.
Both texts are talking about the cause of measles outbreaks(vaccines/unvaccinated)
So how do we get from these complex and unstructured texts to conciseand understandable statements that we can reason over and compare?
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 7 / 25
Texts as collections of propositions
Outline
1 Introduction
2 Texts as collections of propositions
3 Perspectives: attribution & factuality
4 Micro-propositionsWhat are micro-propositions?Why do we need micro-propositions?
5 Future directions
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 8 / 25
Texts as collections of propositions
Propositions
Texts are collections of propositions having reference to events, entitiesand properties in the (real or assumed) world
Expressed, for example, as predicate-argument relations (semantic roles)or modifiers in language
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 9 / 25
Texts as collections of propositions
Propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
outbreak
measles
recent
Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 10 / 25
Texts as collections of propositions
Propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
outbreak
measles
recent
overblown Arg1insanely EXT
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 10 / 25
Texts as collections of propositions
Propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
triggered
outbreak
anti-vaccination movement
measles
recent
Arg1
Arg0
overblowninsanely
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 10 / 25
Texts as collections of propositions
Propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
overblowninsanely
LOC
Arg0
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 10 / 25
Texts as collections of propositions
Propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
causedArg1 personArg0overblowninsanely
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 10 / 25
Texts as collections of propositions
Propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
caused person
vaccinated
recently
overblowninsanely
Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 10 / 25
Texts as collections of propositions
Propositions
Texts are collections of propositions having reference to events, entitiesand properties in the (real or assumed) world
GRaSP model for linking mentions to instances (Fokkens & Vossen, thisafternoon)
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
Arg1
TMP
Arg1
causedArg1 personArg0
vaccinated
recently
Arg0
overblown Arg1insanely EXT
LOC
Arg0 Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 11 / 25
Perspectives: attribution & factuality
Outline
1 Introduction
2 Texts as collections of propositions
3 Perspectives: attribution & factuality
4 Micro-propositionsWhat are micro-propositions?Why do we need micro-propositions?
5 Future directions
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 12 / 25
Perspectives: attribution & factuality
Attribution & Factuality
These propositions are not necessarily the beliefs of the author→ attribution (Roser’s talk this morning)
Attitude of source (author or quoted) expressed towards proposition→ factuality (among many others)
Factuality1 is a combination of:
polarity (affirmative/negative)certainty (certain/probable/possible)
1R. Saurı and J. Pustejovsky. FactBank: A corpus annotated with event factuality. Language resources and evaluation, 43(3):227–268, 2009.
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 13 / 25
Perspectives: attribution & factuality
Attribution & Factuality
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
triggered
outbreak
anti-vaccination movement
Arg1
Arg0
AUTHORTHE MEDIA
AFFIRMATIVEPROBABLE
NEGATIVECERTAIN
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 14 / 25
Perspectives: attribution & factuality
Attribution & Factuality
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
outbreak
at Disneylandstarted LOC
Arg0
AUTHORHEALTH AUTHORITIES
AFFIRMATIVEPROBABLE
NEGATIVECERTAIN
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 14 / 25
Perspectives: attribution & factuality
Attribution & Factuality
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
outbreak causedArg1 personArg0
vaccinated
recently
Arg1
TMP
AUTHOR
ACTUAL SCIENCE
AFFIRMATIVEPROBABLE
NEGATIVECERTAIN
AFFIRMATIVEPROBABLE
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 14 / 25
Micro-propositions
Outline
1 Introduction
2 Texts as collections of propositions
3 Perspectives: attribution & factuality
4 Micro-propositionsWhat are micro-propositions?Why do we need micro-propositions?
5 Future directions
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 15 / 25
Micro-propositions What are micro-propositions?
What are micro-propositions?
Texts are collections of propositions having reference to events, entitiesand properties in the (real or assumed) world
Propositions can be decomposed into micro-propositions
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
Arg1
TMP
Arg1
causedArg1 personArg0
vaccinated
recently
Arg0
overblown Arg1insanely EXT
LOC
Arg0 Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 16 / 25
Micro-propositions What are micro-propositions?
What are micro-propositions?
Texts are collections of propositions having reference to events, entitiesand properties in the (real or assumed) world
Propositions can be decomposed into micro-propositions
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
Arg1
TMP
Arg1
causedArg1 personArg0
vaccinated
recently
Arg0
overblown Arg1insanely EXT
LOC
Arg0 Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 16 / 25
Micro-propositions What are micro-propositions?
What are micro-propositions?
Texts are collections of propositions having reference to events, entitiesand properties in the (real or assumed) world
Propositions can be decomposed into micro-propositions
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
Arg1
TMP
Arg1
causedArg1 personArg0
vaccinated
recently
Arg0
overblown Arg1insanely EXT
LOC
Arg0 Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 16 / 25
Micro-propositions What are micro-propositions?
What are micro-propositions?
Texts are collections of propositions having reference to events, entitiesand properties in the (real or assumed) world
Propositions can be decomposed into micro-propositions
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
Arg1
TMP
Arg1
causedArg1 personArg0
vaccinated
recently
Arg0
overblown Arg1insanely EXT
LOC
Arg0 Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 16 / 25
Micro-propositions What are micro-propositions?
What are micro-propositions?
Texts are collections of propositions having reference to events, entitiesand properties in the (real or assumed) world
Propositions can be decomposed into micro-propositions
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
Arg1
TMP
Arg1
causedArg1 personArg0
vaccinated
recently
Arg0
overblown Arg1insanely EXT
LOC
Arg0 Arg1
TMP
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 16 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
Another example (taken from FactBank)
Two Libyans were suspected of blowing up a Pan Am jumbo jet overScotland in 1988.
two Libyans
blow_up
over ScotlandPan Am jumbo jet
in 1988
Arg0
Arg1
ArgM-TMP
ArgM-LOC
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 17 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
Another example (taken from FactBank)
Two Libyans were suspected of blowing up a Pan Am jumbo jet overScotland in 1988.
two Libyans
blow_up
over ScotlandPan Am jumbo jet
in 1988
Arg0
Arg1
ArgM-TMP
ArgM-LOC
ARBITRARY SOURCE
AFFIRMATIVEPOSSIBLE
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 18 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
Another example (taken from FactBank)
Two Libyans were suspected of blowing up a Pan Am jumbo jet overScotland in 1988.
two Libyans
blow_up
over ScotlandPan Am jumbo jet
in 1988
Arg0
Arg1
ArgM-TMP
ArgM-LOC
ARBITRARY SOURCE
AFFIRMATIVEPOSSIBLE
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 18 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
Another example (taken from FactBank)
Two Libyans were suspected of blowing up a Pan Am jumbo jet overScotland in 1988.
two Libyans
blow_up
over ScotlandPan Am jumbo jet
in 1988
Arg0
Arg1
ArgM-TMP
ArgM-LOC
ARBITRARY SOURCE
AFFIRMATIVECERTAIN
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 18 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
We need to model perspectives (i.e. negation, modality, uncertainty,sentiment, etc.) at the level of micro-propositions
Allows for inference (e.g. implicit positive meaning)
“Vaccines do not cause autism in all children, obviously.”→ vaccines cause autism, but not in all children
“You cannot be vaccinated against malaria.”→ you can be vaccinated, but not against malaria“I don’t want to get the vaccination if it is not necessary.”→ I want to get the vaccination, but not if it is not necessary
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 19 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
We need to model perspectives (i.e. negation, modality, uncertainty,sentiment, etc.) at the level of micro-propositions
Allows for inference (e.g. implicit positive meaning)
“Vaccines do not cause autism in all children, obviously.”→ vaccines cause autism, but not in all children“You cannot be vaccinated against malaria.”→ you can be vaccinated, but not against malaria
“I don’t want to get the vaccination if it is not necessary.”→ I want to get the vaccination, but not if it is not necessary
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 19 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
We need to model perspectives (i.e. negation, modality, uncertainty,sentiment, etc.) at the level of micro-propositions
Allows for inference (e.g. implicit positive meaning)
“Vaccines do not cause autism in all children, obviously.”→ vaccines cause autism, but not in all children“You cannot be vaccinated against malaria.”→ you can be vaccinated, but not against malaria“I don’t want to get the vaccination if it is not necessary.”→ I want to get the vaccination, but not if it is not necessary
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 19 / 25
Micro-propositions Why do we need micro-propositions?
Back to our example
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
outbreak
at Disneylandstarted LOC
Arg0
AUTHORHEALTH AUTHORITIES
AFFIRMATIVEPROBABLE
NEGATIVECERTAIN
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 20 / 25
Micro-propositions Why do we need micro-propositions?
Back to our example
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
outbreak
at Disneylandstarted LOC
Arg0
AUTHORHEALTH AUTHORITIES
AFFIRMATIVEPROBABLE
NEGATIVECERTAIN
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 20 / 25
Micro-propositions Why do we need micro-propositions?
Another reason for micro-propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
imagine acomplete text...
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
caused person
vaccinated
recently
overblowninsanely
spew
tirades
the media
chargedemotionally
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 21 / 25
Micro-propositions Why do we need micro-propositions?
Another reason for micro-propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
imagine acomplete text...
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
caused person
vaccinated
recently
overblowninsanely
spew
tirades
the media
chargedemotionally
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 21 / 25
Micro-propositions Why do we need micro-propositions?
Another reason for micro-propositions
While the media continues to spew emotionally charged tirades about how theanti-vaccination “movement” allegedly triggered the recent measles outbreak that healthauthorities believe started at Disneyland, actual science suggests that the most likely causeof this insanely overblown outbreak was a person who was recently vaccinated.
imagine acomplete text...
triggered
outbreak
at Disneylandstarted
anti-vaccination movement
measles
recent
caused person
vaccinated
recently
overblowninsanely
spew
tirades
the media
chargedemotionally
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 21 / 25
Micro-propositions Why do we need micro-propositions?
Why do we need micro-propositions?
We need to model perspectives (i.e. negation, modality, uncertainty,sentiment, etc.) at the level of micro-propositions
Allows for inference (e.g. implicit positive meaning)
Some micro-propositions are more ‘important’ than others
Which (micro-)propositions contribute information that isold/presupposed?Which (micro-)propositions contribute new, non-derivable or contrastiveinformation that is of high communicative interest?
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 22 / 25
Future directions
Outline
1 Introduction
2 Texts as collections of propositions
3 Perspectives: attribution & factuality
4 Micro-propositionsWhat are micro-propositions?Why do we need micro-propositions?
5 Future directions
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 23 / 25
Future directions
On-going work
Detecting implicit positive meaning from negated/modal statements(inference)
Detecting focus of statements (high communicative interest)
Annotation of these information layers in vaccination corpus
Representation in the GRaSP framework (see Antske’s talk)
Recognizing textual entailment (contradicting/confirming statements)
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 24 / 25
Future directions
Thank you for listening!
van Son et al. (VU Amsterdam) Micro-propositions for text understanding December 15, 2017 25 / 25