BOB WALKED DOWN THE STREET
by David K. Elson
Bob walked down the street one day. He turned a corner and saw a
child. He walked past the child. “Hi,” said the child. “Hi,” said Bob.
After Bob finished walking past the child, he came across a street
corner. Bob walked over the street corner and onto the street. After
crossing the street, he arrived at the opposite corner and started to
walk on the sidewalk again.
Bob continued to walk down the sidewalk. In order to walk, Bob
started by leaning over. Every time he was about to fall over, he put
out a leg. Bob did this over and over again. He switched legs every
time he did it.
Bob kept walking. Did you know that walking has a long history? Bob
did. Bob was proud to be a part of the history of walking. If there had
been a sign about the history of walking, Bob would have walked by it.
Suddenly, Bob felt a burning, painful sensation is his grotesquely
overgrown, tattoo-laden thigh, which bled a cyan-colored ooze.
Suddenly, Bob felt a burning, painful sensation is his grotesquely
overgrown, tattoo-laden thigh, which bled a cyan-colored ooze.
It jolted up through his restraining chains and belts of ammunition until
it reached his neck, cutting off his oxygen. Luckily, he needed none.
Suddenly, Bob felt a burning, painful sensation is his grotesquely
overgrown, tattoo-laden thigh, which bled a cyan-colored ooze.
It jolted up through his restraining chains and belts of ammunition until
it reached his neck, cutting off his oxygen. Luckily, he needed none.
He was hit! He looked at the poison arrows. One had a note:
Suddenly, Bob felt a burning, painful sensation is his grotesquely
overgrown, tattoo-laden thigh, which bled a cyan-colored ooze.
It jolted up through his restraining chains and belts of ammunition until
it reached his neck, cutting off his oxygen. Luckily, he needed none.
He was hit! He looked at the poison arrows. One had a note:
THIS IS REVENGE FOR THE MURDER OF MY FATHER,
THE LEADER OF THE SECRET CULT OF HAMMURABI.
Suddenly, Bob felt a burning, painful sensation is his grotesquely
overgrown, tattoo-laden thigh, which bled a cyan-colored ooze.
It jolted up through his restraining chains and belts of ammunition until
it reached his neck, cutting off his oxygen. Luckily, he needed none.
He was hit! He looked at the poison arrows. One had a note:
THIS IS REVENGE FOR THE MURDER OF MY FATHER,
THE LEADER OF THE SECRET CULT OF HAMMURABI.
IF YOU ARE NOT THE MURDERER,
PLEASE DISREGARD THIS NOTE.
Suddenly, Bob felt a burning, painful sensation is his grotesquely
overgrown, tattoo-laden thigh, which bled a cyan-colored ooze.
It jolted up through his restraining chains and belts of ammunition until
it reached his neck, cutting off his oxygen. Luckily, he needed none.
He was hit! He looked at the poison arrows. One had a note:
THIS IS REVENGE FOR THE MURDER OF MY FATHER,
THE LEADER OF THE SECRET CULT OF HAMMURABI.
IF YOU ARE NOT THE MURDERER,
PLEASE DISREGARD THIS NOTE.
Bob hit a button on his diamond wristwatch, causing all his clothing to
vaporize in a pop that deafened the little girl. He later adopted her.
Suddenly, Bob felt a burning, painful sensation is his grotesquely
overgrown, tattoo-laden thigh, which bled a cyan-colored ooze.
It jolted up through his restraining chains and belts of ammunition until
it reached his neck, cutting off his oxygen. Luckily, he needed none.
He was hit! He looked at the poison arrows. One had a note:
THIS IS REVENGE FOR THE MURDER OF MY FATHER,
THE LEADER OF THE SECRET CULT OF HAMMURABI.
IF YOU ARE NOT THE MURDERER,
PLEASE DISREGARD THIS NOTE.
Bob hit a button on his diamond wristwatch, causing all his clothing to
vaporize in a pop that deafened the little girl. He later adopted her.
But Bob wasn’t nude for long. One by one, long, poison-tipped purple
spikes protruded from each pore of his decayed skin.
• Why do we find stories interesting?
• Is there a pattern that good stories follow?
• What good would such a model be?
NL Generation and
Understanding Through
Narrative
David K. Elson
December 2, 2003
11
The Plot
1. Why study narrative?
2.
3.
4.
5.
What is narrative?
What makes stories
interesting?
How have stories been
modeled?
What’s the new idea?
12
My Own Story
• Columbia CS degree
• NLP employee
– Newsblaster project
• Filmmaker
– Project started out of writer’s block
• Masters student
– Project geared toward news summarization
13
Many Tasks for Stories
1.
2.
3.
4.
5.
News
Biographies
Entertainment
History
World View
•
Allegories, cautionary tales, fables, myths
6. Social interaction
•
Gossip
14
A Specialized Model
• You know statistical language models
– Used for generation, knowledge detection
– “Expectation” analogous to news & pitching
• A higher-level narrative model can take
advantage of this structure
– Potential for better generation and understanding
for many texts
– Not all texts are narrative
15
Why study interestingness?
• A story fails at the tasks if people find it boring
– Is interestingness “deterministic?”
• Therefore, to understand how stories work is
to understand when stories are interesting
16
What else is there to study?
• Anthropology: studies of myth
• Theory:
– Literary semiotics, structuralism
– Definitional questions
• What is a story? What is not a story?
– Fictional “recentering”
• Psychology and cognition:
– Constructing an image from language
– Narrative in development: nature or nurture?
– Narrative views of memory and self-identity
17
My mission:
• Create a model of story anatomy
• Understand how stories create interest
• Implement the model on the computer
– Story generation and understanding
– News summarization
– Predict levels of human interest
18
The Plot
1.
Why study narrative?
2. What is narrative?
3.
4.
5.
What makes stories
interesting?
How have stories been
modeled?
What’s the new idea?
19
General definition
• Multiple layers to a story
– What the story is, and how the story is told
– Content vs. style of delivery
• An additional distinction:
20
Layers of narrative
Discourse
Story
Observed
Implied
Fabula
21
Fabula
Elements of a fabula
• Characters (actors)
– Goals and objects of goals
• Raw set of world events
–
–
–
–
“Actual” or imagined by characters
Causally related
Abstract: no interpretation or expression
Ordered in a timeline
22
Fabula
John’s Story: Fabula
0


FABULA 

TIME

LINE



John applies to Columbia.
John gets into Columbia.
John picks his nose.
John goes to his first class.
John and Judy meet in class.
John tells his Columbia story to Judy.
John leaves class.
John and Helen meet.
23
Layers of narrative
Discourse
Story
Fabula
24
Story
• A focalizer perceives the fabula in a
sequence of observations
– The point of view.
• Fabula events are selected or dismissed.
• Understanding narrative means discerning
the fabula from the story.
– Analogous to computer vision
25
Story
• Who can be a focalizer?
– An external narrator
• The sun set over John going to his first class
– A character in the story
• I saw John go to his first class
• Laura saw John go to his first class
26
Story
John’s Story: Focalization #1
“College Promotional Video”
(external focalizer)
–
–
–
–
John applied to Columbia.
John went to his first class.
John listened furiously.
John ran into a high school
sweetheart.
27
Story
John’s Story: Focalization #2
“Judy Meets a Nut”
(Judy as focalizer)
– Judy met John in class.
– John babbled about his experience:
– His applying to school.
Jump backward
in timeline
– His getting into school.
– John left and flirted with some girl.
28
Story
Plot is a good name
FABULA
TIME
LINE
0
Standard scene
PLOT (STORY) TIME
29
Story
Plot is a good name
FABULA
TIME
LINE
0
Narrative break
(ellipsis)
PLOT (STORY) TIME
30
Story
Plot is a good name
FABULA
TIME
LINE
0
Montage
(summary)
PLOT (STORY) TIME
31
Story
Plot is a good name
FABULA
TIME
LINE
Flashback
0
PLOT (STORY) TIME
32
Story
Plot is a good name
told twice
FABULA
TIME
LINE
0
“Circular” structure
(Much news,
Pulp Fiction,
The Usual Suspects)
PLOT (STORY) TIME
33
Story
Plot is a good name
FABULA
TIME
LINE
Memento
0
PLOT (STORY) TIME
34
Story
Plot is a good name
FABULA
TIME
LINE
Multiple focalizers (Rashomon, Poisonwood Bible)
0
PLOT (STORY) TIME
35
Layers of narrative
Discourse
Story
Fabula
36
Discourse
• The surface depiction of the story
• Many “genres” of narrative discourse:
•
•
•
•
•
•
Written prose
Stage drama
Cinema
Poetry
Hieroglyphs
Shadow puppets
37
Discourse
A story is told by a narrative agent
• Closely related to focalizer
– Can be same “entity” or different
• Can be external or central to story
• Uses the tools of the medium to enhance the
effect of the story on the audience
– Interprets what the effect should be
• This is style
38
Discourse
The narrative agent’s tools in prose
•
•
•
•
•
•
•
•
•
Descriptions of actions
Quotations of speech
Selection of details
Comments and descriptions
Imagery
Foreshadowing
Grammar and word usage
Ideological pontifications
Historical digressions
39
Discourse
The narrative agent’s tools in drama
•
•
•
•
•
•
•
Scene selection
Blocking
Dialogue
Set design
Lighting
Casting
Performance
40
Discourse
The narrative agent’s tools in cinema
•
•
•
•
•
•
•
Scene selection
Blocking
Dialogue
Set design
Lighting
Casting
Performance
•
•
•
•
•
Editing
Music
Camera placement
Lens selection
Depth of field
41
The Plot
1.
2.
Why study narrative?
What is narrative?
3. What makes stories
interesting?
4.
5.
How have stories been
modeled?
What’s the new idea?
42
How was the book?
•
•
•
•
•
•
•
•
Good story, but badly told
No story, but interesting anyway
I liked the main character, but nothing happened to him
The plot was OK, but I couldn’t stand the characters
Good story, but I don’t really care about the subject
Not very interesting, but I’m really into the subject
Fascinating setting, but story didn’t do it justice
I guess it was entertaining, but it didn’t take me
anywhere I haven’t been before
43
Interestingness is a product
STORY
DISCOURSE
(TELLING)
LISTENER
RELEVANCE
X
*
Y
*
Z
= NARRATIVE INTERESTINGNESS
44
STORY
DISCOURSE
(TELLING)
LISTENER
RELEVANCE
X
*
Y
*
Z
= NARRATIVE INTERESTINGNESS
45
STORY
46
STORY
PLOT
CHARACTER
WORLD
a
*
b
*
= X (story interestingness)
c
47
STORY
What’s a good story?
• Suspenseful plot
• Interesting characters
• Immersing world
48
Innate questions let us crave stories
• Suspenseful plot
– “How should I handle what may happen to
me?”
• Interesting characters
– “What kind of person should I be?”
• Immersing world
– “What’s out there?”
49
PLOT
“How should I handle what may
happen to me?”
•
•
•
•
Character goals we care about
Obstacles we haven’t thought of
Conflicts with others we may have to face
Solutions we couldn’t have thought of
50
CHARACTER
“What kind of person should I be?”
• Value systems and character traits are rewarded and
punished
– More on this later
• Characters have flaws we should avoid
• People or organizations with opposing traits are
contrasted
• Traits are in unusual combinations or run against
stereotypes
51
WORLD
“What’s out there?”
• Different societies with different styles
– Foreign places and times
– Unfamiliar social organizations
• Subcultures
– Professions, ethnic groups, special-interest groups
• “Theme” or “world view”
– E.g., industrialization, isolation, repression
52
STORY
DISCOURSE
(TELLING)
LISTENER
RELEVANCE
X
*
Y
*
Z
= NARRATIVE INTERESTINGNESS
53
DISCOURSE
(TELLING)
“Well told,” how?
•
•
•
•
•
Sympathetic portrayal of hero and cause
Unpredictability
Novelty
Suspenseful retention of plot developments
Descriptive details for world immersion
– Setting, dialogue, lifestyles
• Humor and scares at the right times
54
STORY
DISCOURSE
(TELLING)
LISTENER
RELEVANCE
X
*
Y
*
Z
= NARRATIVE INTERESTINGNESS
55
LISTENER
RELEVANCE
Two issues:
1. Interest is subjective
2. A story has a variable relevance or similarity
to perceiver’s own life
56
LISTENER
RELEVANCE
Personal relevance
•
One may identify more or less with the character’s
wants
–
•
One may or may not agree with the world view
–
•
Not everyone cares about teen love, horse racing, etc.
Richard Gerrig research on political news summarization
“Based on a true story” as a selling point
• Events that really happened better satisfy the
“innate questions”
57
LISTENER
RELEVANCE
Example: News
Man in Singapore
wins Nobel Prize
SIGNIFICANCE
Man in Singapore
slips and breaks his
ankle
Man in Columbia
creative writing
department wins
Nobel Prize
Man in Columbia
creative writing
department slips and
breaks his ankle
LOCALITY
58
LISTENER
RELEVANCE
Example: News
Most likely to be in the Spectator
Man in Singapore
wins Nobel Prize
SIGNIFICANCE
Man in Singapore
slips and breaks his
ankle
Least likely to
be in the Spectator
Man in Columbia
creative writing
department wins
Nobel Prize
Man in Columbia
creative writing
department slips and
breaks his ankle
LOCALITY
59
The Plot
1.
2.
3.
Why study narrative?
What is narrative?
What makes stories
interesting?
4. How have stories been
modeled?
5.
What’s the new idea?
60
Everyone wants a model
Story
Generation
Psychology
Literary
Theory
Model of
Interesting Stories
Story
Understanding
61
Types of models
Plot Fragments
Frames
Grammars
Marker Passing
62
Literary
Theory
Campbell
Plot Fragments
• 1949: Mythologist Joseph Campbell publishes Hero
with a Thousand Faces
– Societal and psychological importance of myth
– Myth as cultural heritage
– Myth archplots:
• Call to adventure and refusal of call
• Threshold crossing, dragon-battle, dismemberment,
crucifixion, abduction, wonder journey, whale’s belly
• Return, rescue, resurrection, threshold struggle
• Sacred marriage, father atonement, apotheosis
• Still not formal or complete enough to be useful
63
Literary
Theory
Propp
Plot Fragments
• 1923: Russian Formalist Vladimir Propp looks at the
Morphology of a Folk Tale
• Most Russian folk tales draw from a pool of 31 plot
fragments
–
–
–
–
–
–
The hero leaves home
The villain attempts to deceive the victim
The hero and villain join in direct combat
The false hero or villain is exposed
The villain is exposed
The hero marries and ascends to the throne
• A grammar dictates how the fragments fit together
64
Story
Understanding
Early
Software
Plot Fragments
• SAM: Script Applier Mechaism (Cullingford, 1978)
– Reads NL text into causal chains
– Rigid knowledge base and inference engine
– Small input tolerance (only handles trivial stories)
• PAM: Plan Applier Mechanism (Wilensky 1978)
– Models around character goals, infers motivations
– Still heavy reliance on inference engine, knowledge base
– Still can’t handle real stories
• TALE-SPIN: first generator (Meehan 1979)
– On-the-fly problem solving
– Stories are often not interesting, little conflict
65
Story
Understanding
•
Mid-80s
Marker Passing
FAUSTUS (Norvig 1987) and ATLAST (Eiselt 1987)
are marker passing systems
–
–
–
Less bound by rigid scripts and frames than SAM and
PAM
Markers are “passed” through the semantic network until
they run out of “energy”
Strong inferences are drawn, weak ones dismissed
66
Story
Understanding
•
•
Rumelhart
Grammars
1975: David E. Rumelhart
Syntactic rules for story structure:
– Rule 1: Story  Setting + Episode
– Rule 6: Internal Response  (Emotion | Desire)
– Rule 10: Preaction  Subgoal + (Attempt)*
•
Summarization rewrite rules
–
•
Summary(CAUSE[X,Y])  “Instrument(X) caused (Y)”
Grammar is not powerful, but very influential
67
Story
Generation
MINSTREL
Frames
• Scott Turner 1992
• Story generation and surface rendering
• Models the human process of storytelling
– Consistency, suspense, fulfillment of themes
• Appears “creative” with case-base reasoning
– Recalls, adapts, and applies previous solutions
• Domain: King Arthur’s Court
– Goals include obtaining wives, slaying dragons
68
Today: Rebirth
• Away from the symbolic, toward the practical
• 1999: AAAI Symposium on Narrative Intelligence
–
–
–
–
–
MIT: Narrative as retold in social networks (Usenet)
MIT Media Lab: Converting travelogues to narrative form
Swedish Institute of CS: Browsing the Web in narrative
Brenda Laurel: interfaces with characters, metaphors
IIT (Canada): Narrative with autonomous agents
– New definitions, new models
• Based on conflict between characters (Szilas)
• Based on the reader’s reaction (Bailey)
• Based on new grammars (Lang)
69
Story
Generation
BRUTUS.1
Grammars
• 2000: Selmer Bringsjord and David Ferrucci (RPI)
• Story generation and discourse rendering
• Formal representation of dramatic themes
– Betrayal, self-deception
• Renders with both grammars and simulations
– Literary techniques (irony, metaphor)
• Domain: a student’s dissertation defense
– Very small!
– Don’t know how “serious” this is, but a lot of press!
70
The Plot
1.
2.
3.
4.
Why study narrative?
What is narrative?
What makes stories
interesting?
How have stories been
modeled?
5. What’s the new idea?
Aesop
71
A new goal
1. Create a model of interesting situations.
2. Make it powerful enough to generate the
essence of any real-life dramatic story,
fiction or nonfiction.
3. Yet, make it specific enough to be useful.
72
The new approach
•
•
•
•
Don’t write a surface generator.
Don’t need a complex inference engine.
Just design high-level plots.
Keep its use statistical.
– Avoid the need for a rigid knowledge base.
73
The new model
• A story is interesting when a character has
a set of wants and faces difficulty in
satisfying them.
• What can a character want?
74
Character wants
•
•
•
•
•
•
•
•
•
•
•
Life
Physical health
Mental health
To be physically home
The wants of family
The wants of clan
Freedom of movement
Freedom of behavior
Companionship
Privacy
Etc.
75
Plot Arcs, Not Inference
• PLOT ARCS are found in a text:
–
–
–
–
A character seeks redemption from a past mistake
A character is falsely accused of a crime
A neglected veteran gets a chance to be a hero again
A character seeks to rescue an endangered SYMBOL of a
want
• Person, object, etc.
• Also have models for CHARACTERS, THEMES,
WORLDS, DYNAMICS (between characters).
76
Value Systems
• Each character assigns a comparable value
to all her wants.
• This captures many interesting situations:
– Plots: Sacrifice of one want for another
• Suicide bombers, whistle-blowers
– Characters: Unusual or “evil” value systems
• We are surprised at a choice of sacrifice
• Ruthless villains value others’ lives lower
77
Clans
• Any subset of the population with a common
bond forms a clan.
– Ethnic group, socio-economic group, special
interest group, family
• This captures many interesting situations:
– Plots: love across clan boundaries, struggling to
join or leave a clan, war between clans
– Characters: conflicted on a clan boundary, the
leader of a clan, having traits against the clan’s
stereotypes
– Worlds: the end of a clan
78
The technical issues
•
How will plot arcs fit together?
–
–
–
•
•
Like a grammar?
Independent “motifs?”
Schemas?
How much of a knowledge base is needed?
How can this help news summarization?
–
–
–
Let plot elements guide extraction
Define plot-specific schemas
Generate new sentences
79
Classifying the news
• JERUSALEM (CNN) -- The Israeli military has embarked on a
wide-ranging raid in Jenin after getting tips that the Palestinian
militant group Islamic Jihad was planning to carry out terror
attacks against Israel from the northern part of the West Bank,
the Israel Defense Forces said Thursday.
80
Classifying the news
• JERUSALEM (CNN) -- The Israeli military has embarked on a
wide-ranging raid in Jenin after getting tips that the Palestinian
militant group Islamic Jihad was planning to carry out terror
attacks against Israel from the northern part of the West Bank,
the Israel Defense Forces said Thursday.
• Applicable plot arcs:
– [ PREEMPTIVE STRIKE AGAINST
[ POTENTIAL FOR
[ MURDER OF INNOCENT ] ] ]
– [ BETRAYAL OF [ SECRET ] ]
– [ RESISTANCE TO [ POLITICAL OPPRESSION ] ]
81
Classifying the news
• JERUSALEM (CNN) -- The Israeli military has embarked on a
wide-ranging raid in Jenin after getting tips that the Palestinian
militant group Islamic Jihad was planning to carry out terror
attacks against Israel from the northern part of the West Bank,
the Israel Defense Forces said Thursday.
FABULA
TIME
LINE
New events - action
Old events - motivation
ARTICLE TEXT
82
Classifying the news
• JERUSALEM (CNN) -- The Israeli military has embarked on a
wide-ranging raid in Jenin after getting tips that the Palestinian
militant group Islamic Jihad was planning to carry out terror
attacks against Israel from the northern part of the West Bank,
the Israel Defense Forces said Thursday.
• Retold, linear story:
– Islamic Jihad wanted to attack Israel, and to
defend itself, Israel responded by raiding Jenin.
83
The big issues
• In the end, all stories are formulaic, for
sufficiently small formulas.
– You can write “new” sentences, even though all its
words have been used before and cataloged
• We can catalog and organize these formulas.
• A working model could be useful in many
domains, including NLP.
84
So please…
STAY TUNED!
And
THANK YOU!
85
THE END
86