Transcript PSY 369: Psycholinguistics - the Department of Psychology at

PSY 369: Psycholinguistics
Language Comprehension:
Discourse
Discourse Psycholinguistics

Traditional Psycholinguistics


Determining what happens when we understand sentences
Broader View

How we resolve/understand sentences against the current
discourse representation

Sentence comprehension is a process that anchors the
interpretation of the sentence to the representation of the prior
text
Processing Discourse

What is discourse?

The ways that we process (i.e., comprehend and
remember) units of language larger than a sentence


Lectures, personal narratives, expository discourse
Units of analysis larger than a sentence

Applies to both spoken and written forms
Discourse processing is sort of like syntactic
processing – a way of organizing/connecting
the different pieces in to larger chunks. Here
the chunks are larger than sentences.
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”

To whom does “him” refer to?
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”

To whom does “him” refer?
Bach
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”

To whom does this “him” refer?
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”

To whom does this “him” refer?
Bach again
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”

To whom does this “him” refer?
Bach again
Why not Abe?
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”

Huh!?
Bill and Ted traveled through time and space.
Bill asked, “Dude, did you find him?”
“Yeah, Bach was in the music store, but I haven’t found Abe
yet. Dude, you should hear him play, he rocks!”
“Excellent! Man, we’ve got to get these dudes back to
school before we get there.”

Huh!?
Oh yeah, they’re time travelers.
Characteristics of Discourse

Local Structure (microstructure):

The relationship between individual sentences



Cohesion
Coherence
Global Structure (macrostructure):

The relationship between the sentences and our
knowledge of the world
Characteristics of Discourse

Local Structure (microstructure):

The relationship between individual sentences



Cohesion
Coherence
Global Structure (macrostructure):

The relationship between the sentences and our
knowledge of the world
Characteristics of Discourse

Local Structure (microstructure):

The relationship between individual sentences


Cohesion
• Does the discourse “stick together”?
• Interpretation of one sentence depends on other
sentences?
Coherence
• Does the passage make sense?
• Logical consistency and semantic continuity?
Characteristics of Discourse

Cohesion: Interpretation of one sentence
depends on other sentences

Referential Cohesion


Substitution Cohesion


“We’ve got to get these dudes back to …”
And many more


“Dude, you should hear him play…”
Ellipsis, conjunction, lexical cohesion (See pg 160 of
textbook for examples)
The relationship between the referring expression
and the antecedent create referential cohesion of
discourse
Types of Referential Cohesion

Anaphoric Reference

Using an expression to refer back to something previously
mentioned in discourse
“…Bach was in the music store …”
“Dude, you should hear him play, he rocks.”

Cataphoric Reference

Using an expression to refer forward to something that is
coming up in discourse
Dude, did you find him?”
“Yeah, Bach was in the music store...”
Comprehending Anaphoric References
Daneman and Carpenter (1980)

Task: Reading a passage and answer questions about the referents of
pronouns
Sitting with Richie, Archie, Walter and the rest of my gang in the Grill yesterday, I began to
feel uneasy. Robbie had put a dime in the juke box. It was blaring one of the latest
“Rock and Roll” favorites. I was studying, in horror, the reactions of my friends to the
music. I was especially perturbed by the expression on my best friend’s face. Wayne
looked intense and was pounding the table furiously to the beat. Now, I like most of
the things other teenage boys like. I like girls with soft blonde hair, girls with dark curly
hair, in fact all girls. I like milkshakes, football games and beach parties. I like denim
jeans, fancy T-shirts and sneakers. It is not that I dislike rock music but I think it is
supposed to be fun and not taken too seriously. And here he was, “all shook up” and
serious over the crazy music.
Question: Who was “all shook up” and serious over the music?
Comprehending Anaphoric References
Daneman and Carpenter (1980)

Task: Reading a passage and answer questions about the referents of
pronouns
Sitting with Richie, Archie, Walter and the rest of my gang in the Grill yesterday, I began to
feel uneasy. Robbie had put a dime in the juke box. It was blaring one of the latest
“Rock and Roll” favorites. I was studying, in horror, the reactions of my friends to the
music. I was especially perturbed by the expression on my best friend’s face. Wayne
looked intense and was pounding the table furiously to the beat. Now, I like most of
the things other teenage boys like. I like girls with soft blonde hair, girls with dark curly
hair, in fact all girls. I like milkshakes, football games and beach parties. I like denim
jeans, fancy T-shirts and sneakers. It is not that I dislike rock music but I think it is
supposed to be fun and not taken too seriously. And here he was, “all shook up” and
serious over the crazy music.
Question: Who was “all shook up” and serious over the music?
Comprehending Anaphoric References
Daneman and Carpenter (1980)

Task: Reading a passage and answer questions about the referents of
pronouns
Sitting with Richie, Archie, Walter and the rest of my gang in the Grill yesterday, I began to
feel uneasy. Robbie had put a dime in the juke box. It was blaring one of the latest
“Rock and Roll” favorites. I was studying, in horror, the reactions of my friends to the
music. I was especially perturbed by the expression on my best friend’s face. Wayne
looked intense and was pounding the table furiously to the beat. Now, I like most of
the things other teenage boys like. I like girls with soft blonde hair, girls with dark curly
hair, in fact all girls. I like milkshakes, football games and beach parties. I like denim
jeans, fancy T-shirts and sneakers. It is not that I dislike rock music but I think it is
supposed to be fun and not taken too seriously. And here he was, “all shook up” and
serious over the crazy music.
Question: Who was “all shook up” and serious over the music?
 Reading Span Test


Smaller reading spans = smaller working memory capacity
Manipulated how many sentences intervened between the
pronoun ‘he’ and the antecedent ‘Wayne’
Comprehending Anaphoric References
Daneman and Carpenter (1980)


Conclusions: The number of intervening sentences don’t
matter for high span people, but does for low span
Results
Characteristics of Discourse

Coherence:

Given/new distinction


•
•
Readers expect speakers to provide cues as to what
information is old (already known by the listener) and what
is new (not known)
Making Inferences
 Filling in missing pieces of information to maintain
coherence
Haviland and Clark (1974)
Singer, Halldorson, Lear, & Andrusiak (1992)
Developing coherence
Haviland and Clark (1974)

Process of understanding a sentence in discourse
context involves 3 stages:
1. Identify the given and new info in the current sentence
2. Find an antecedent in memory for the given
information
3. Attach the new information to this spot in memory
Developing coherence
Haviland and Clark (1974)

Task: Press a button when you understand the sentence.
We got some beer out of the trunk. The beer was warm.
Developing coherence
Haviland and Clark (1974)

Task: Press a button when you understand the sentence.
We got some beer out of the trunk. The beer was warm.
Definite article “The” signals that “The beer” is given information
Developing coherence
Haviland and Clark (1974)

Task: Press a button when you understand the sentence.
We got some beer out of the trunk. The beer was warm.
Definite article “The” signals that “The beer” is given information
Connect the new information “was warm” to the appropriate
discourse concept
“some beer”
This process is called Direct Matching
Developing coherence
Haviland and Clark (1974)

knowledge
Task: Press a button when you understand theWorld
sentence.
We checked the picnic supplies. The beer was warm.
Definite article “The” signals that “The beer” is given information
Connect the new information “was warm” to the appropriate
discourse concept
“??”
Developing coherence
Haviland and Clark (1974)

knowledge
Task: Press a button when you understand theWorld
sentence.
We checked the picnic supplies. The beer was warm.
Definite article “The” signals that “The beer” is given information
Connect the new information “was warm” to the appropriate
discourse concept
“picnic supplies”
Need a bridging inference to connect “the warm
beer” to “picnic supplies”
Developing coherence
Haviland and Clark (1974)



Task: Press a button when you understand the sentence.
Conclusion: If you don’t know the old information and need to
make an inference, this may slow down comprehension.
Direct Matching
Typical results
We got some beer out of the trunk. The beer was warm.
Comprehended
faster

Bridging Inference
We checked the picnic supplies. The beer was warm.
Takes more
time
World knowledge
Developing coherence
Singer, Halldorson, Lear, & Andrusiak (1992)


Task: Press a button when you understand the sentence, if
given a question, answer Yes or No.
Conclusions:


Suggests that the bridging inference was made
More time consuming to make coherence of temporal than causal
relations
Causal condition
Requires
bridging inference
“Murray poured water on the fire.”
“The fire went out.”
Results
Faster reading time
T/F “water extinguishes fire”
Temporal condition “Murray drank a glass of water.”
No required
“The fire went out.”
inference
T/F “Does water extinguish fire?”
Faster “T”
Brief summary

Local Structure (microstructure):



Discourse is coherent if its elements are easily related.
Coherence is achieved with cohesive ties between
sentences.
Comprehension is impeded when
 There are no antecedents, forcing a bridging inference
 The antecedent was not recent, forcing a
reinstatement of the antecedent.
Characteristics of Discourse

Local Structure (microstructure):

The relationship between individual sentences



Coherence
Cohesion
Global Structure (macrostructure):

The relationship between the sentences and our
knowledge of the world
Characteristics of Discourse

Global Structure (macrostructure):

The relationship between the sentences and our
knowledge of the world
Jill bought a new sweater. Sweaters are sometimes made of
wool. Wool production gives some farmers a good livelihood.
Farming is a high-risk business. On the news last night, I
saw a group of business executives discussing recent trends
in the stock market.

Okay local structure, but each sentence isn’t
relevant to an overall topic of discourse
Characteristics of Discourse

Read story to class (from Bartlett, 1932)
Characteristics of Discourse

Global Structure (macrostructure):

Schemas (Scripts)


General knowledge structures for common social
situations
Genres

Narrative structure


Story grammars - extension of idea of grammatical
rules, specify the organization of a story
Expository structure

Different structures
Characteristics of Discourse

Global Structure (macrostructure):

Schemas (Scripts)


General knowledge structures for common social
situations
Genres

Narrative structure


Story grammars - extension of idea of grammatical
rules, specify the organization of a story
Expository structure

Different structures
Effects of world knowledge
If the balloons pooped, the sound would not be able to
carry since everything would be too far away from the
correct floor. A closed window would also prevent the
sound from carrying since most buildings tend to be
well insulated. Since the whole operation depends on
a steady flow of electricity, a break in the middle of the
wire would also cause problems. Of course the fellow
could shout, but the human voice is not loud enough to
carry that far. An additional problem is that a string
could break on the instrument. Then there could be no
accompaniment to the message. It is clear that the
best situation would involve less distance. Then there
would be fewer potential problems. With face to face
contact, the least number of things could go wrong.

Bransford & Johnson (1972)
Effects of world knowledge
Rocky slowly got up from the mat, planning his escape. He
hesitated a moment and thought. Things were not going well.
What bothered him most was being held, especially since the
charges against him had been weak. He considered his
present situation. The lock that held him was strong but he
thought he could break it. He knew, however, that his timing
would have to be perfect.
Prison escape
OR
Wrestling match

Anderson et al (1977)
Effects of world knowledge

Schemas (Scripts)

Mental structures of how the world works,
acquired through experience

A whole package of information about what we
know about the world and events



Generic story of situations
A framework with causal information
Used to facilitate comprehension of discourse, as
well as to guide recall (and reconstruction)
Effects of world knowledge

Schemas (Scripts)

Generic story of situations
Restaurant Script
Scene 1: Enter
Scene 2: Order
Scene 3: Eat
Scene 4: Pay
Go inside
Go to table
Sit down
Get menu
Read menu
Choose food
Give order
Get food
Eat food
Ask for check
Received check
Tip waiter
Pay check
Exit
Effects of world knowledge
Bartlett (1932)

Task:



Read native American folk tale
Write down everything that you can remember
from that story that I read earlier
Bartlett had them recall after a longer periods of
time (between 15 mins. Up to 10 years later)
Effects of world knowledge
Bartlett (1932)

Results:
 Participants’ memories changed to fit their
existing beliefs (reconstructive memories)
Added new details
 Changed details
 Deleted details
Conclusions: We use our Schema to facilitate
comprehension of discourse, as well as to guide
recall (and reconstruction)


Effects of world knowledge
Invernizzi & Abouzeid (1995)


Read two European tales (cry wolf & stone soup)
2 audiences


European North American children
Ponam children (New Guinea)
Effects of world knowledge
Invernizzi & Abouzeid (1995)


Retelling of boy who cried wolf
Ponam children (New Guinea)

Once upon a time Kalai and his family they lived on an island.
Kalai’s mother always carried him everywhere. One day Kalai’s
mother and father went out fishing. Kalai’s mother said, “Kalai,
you are too small to go out fishing in the sea. You should stay
home with your grandfather.” Kalai was lonely on the beach.
Kalai said, “How could I get my family home?” He sat down and
decided to get his family home. He got his red laplap and ran
down to the beach and waved his laplap to his family and said,
“Fire, fire.” His brother saw his laplap and went home. When
they arrived they saw nothing.
Effects of world knowledge
Invernizzi & Abouzeid (1995)


Retelling of boy who cried wolf
European North American children

Kalai was running up and down the beach yelling “Fire, fire.”
Everybody came home. The next day the same thing
happened. They came home. The next day came, but the
house caught on fire. He ran up and down the beach, but
nobody came. Kalai kept waving the flag. Nobody came.
Suddenly they saw the flames and the smoke and they came,
but it was too late. Everything had burnt down to the ground,
and his brother told him if he kept telling lies that nobody will
come when you call for help.
Effects of world knowledge
Invernizzi & Abouzeid (1995)


Impact of different schemata
European North American children


Ponam children (New Guinea)
Recalled factual detail about settings, events, and
outcomes, but leaving out things like consequence,
resolution, moral (generally seemed to miss the
point)
Conclusions: We use our cultural schemas to facilitate
comprehension of discourse, as well as to guide recall


Setting, precipitating events, goal reaching
aspects, story resolutions
Effects of world knowledge
When do we use the schema? During
comprehension or recall?
Smith and Swinney (1992)


Task: presented stories (like the “balloons” one)




Results:



Collected sentence by sentence reading times
Had them recall the sentences
Some people were given a title for the story, others not
Overall, reading times were faster with a title that without
Stories with titles: More words were recalled and more
“intrusions” (details consistent with the schema but not in the
story)
Conclusions:

Schemas are used in both on-line comprehension and recall
Effects of world knowledge

Summary

We use schemas to
 Facilitate the comprehension of discourse
 To guide recall (and reconstruction)
Effects of Genre

Not all kinds of discourse follow the same
structure

Different effects, purposes, etc.

Expository discourse


Narrative discourse



Convey info about a subject (e.g., textbook, lecture)
Tell a story: Introduce characters & settings, establish
a goal, etc.
APA style
Newspaper articles
Expository Structure

Reading texts, listening to lectures, etc.


Organized with different relationships (but can still draw a tree
structure)
Relationships





Collection - ideas or events related on the basis of some commonality
Causation - ideas are joined causally so that one idea is identified as
the antecedent and another as the consequence
Response - ideas are joined in a problem/solution or question/answer
relationship
Comparison - ideas are related by pointing out similarities and
differences
Description - general ideas are explained by giving attributes or other
specific details
Narrative structure
Once there was a woman. She saw a tiger’s
cave. She wanted a tiger’s whisker. She put
food in front of the cave. The tiger came out.
She pulled out a whisker.

The story has a structure, a story grammar
Narrative structure

Story grammar - can depict with a tree structure
Story
Setting Episode
Once there was a woman.
Event
Reaction
She saw a tiger’s cave.
Goal
She wanted a tiger’s whisker.
Overt Response
Action Consequence
She put food in front of the cave.
Event
The tiger came out.
Event
She pulled out a whisker.
Narrative structure
Thorndyke (1977)

Level effect

High hierarchy statements
Lower in the hierarchy.


Read more
slowly but
are better
remembered.
Comprehensibility and recall were tied to inherent plot
structure, independent of passage content
She wanted a tiger’s whisker.
The tiger came out.
Characteristics of Discourse
Trabasso & Suh (1993)

Test to see if structure effects whether inferences are
made

Task: Think aloud task

Read through the story aloud (one sentence at a time) and
talk aloud about their understanding of that sentence
Trabasso & Suh (1993)
Sequential version
Hierarchical version
Once there was a girl named Betty.
One day, Betty found that her mother’s birthday was coming soon.
Betty really wanted to give her mother a present.
Betty went to the department store.
Betty found a pretty purse.
Betty found that everything was too expensive.
Betty bought the purse.
Betty could not buy anything.
Her mother was very happy.
Betty felt sorry.
Several days later, Betty saw her friend knitting.
Betty was good at knitting.
Betty decided to knit a sweater.
How does
this sentence connect up
Betty selected a pattern from a magazine.
withBetty
thefollowed
rest ofthe
the
story? in the article.
instructions
Finally, Betty finished a beautiful sweater.
Betty pressed the sweater.
Betty folded the sweater carefully.
Betty put it in the closet for the
Betty gave the sweater to her mother.
next time she was going out.
Her mother was excited when she
Berry was very happy.
saw the present.
Trabasso & Suh (1993)
Hierarchical version
S Once there was a girl named Betty.
E One day, Betty found that her mother’s birthday
G
A
O
O
R
E
was coming soon.
Betty really wanted to give her mother a present.
Betty went to the department store.
Betty found that everything was too expensive.
Betty could not buy anything.
Betty felt sorry.
Several days later, Betty saw her friend knitting.
S = Setting
E = Event
R = Reaction
G = Goal
O = Overt Response
A = Action
S
G
A
A
O
A
A
O
R
Betty was good at knitting.
Betty decided to knit a sweater.
Betty selected a pattern from a magazine.
Betty followed the instructions in the article.
Finally, Betty finished a beautiful sweater.
Betty pressed the sweater.
Betty folded the sweater carefully.
Betty gave the sweater to her mother.
Her mother was excited when she saw the
present.
Trabasso & Suh (1993)
Hierarchical version
S Once there was a girl named Betty.
E One day, Betty found that her mother’s birthday
G
A
O
O
R
E
was coming soon.
Betty really wanted to give her mother a present.
Betty went to the department store.
Betty found that everything was too expensive.
Betty could not buy anything.
Betty felt sorry.
Several days later, Betty saw her friend knitting.
S
G
A
A
O
A
A
O
R
Betty was good at knitting.
Betty decided to knit a sweater.
Betty selected a pattern from a magazine.
Betty followed the instructions in the article.
Finally, Betty finished a beautiful sweater.
Betty pressed the sweater.
Betty folded the sweater carefully.
Betty gave the sweater to her mother.
Her mother was excited when she saw the
present.
Is a superordinate goal that motivates the subgoal of the next episode
S
E
G
A
E
O
S
O
G
R
A
A
A
O
A
O
R
Trabasso & Suh (1993)
Sequential version
S Once there was a girl named Betty.
E One day, Betty found that her mother’s birthday
G
A
O
O
R
E
Betty was good at knitting.
Betty decided to knit a sweater.
Betty selected a pattern from a magazine.
Betty followed the instructions in the article.
Finally, Betty finished a beautiful sweater.
Betty pressed the sweater.
Betty folded the sweater carefully.
Betty put it in the closet for the next time she
was going out.
R Berry was very happy.
S
G
A
A
O
A
A
O
was coming soon.
Betty really wanted to give her mother a present.
Betty went to the department store.
Betty found a pretty purse.
Betty bought the purse.
Her mother was very happy.
Several days later, Betty saw her friend knitting.
The goal is already filled, so not related to the subgoal of the next episode
S
E
G
A
O
E
O
S
R
G
A
A
O
A
A
O
Trabasso & Suh (1993)
Results

In a think aloud task
 participants mentioned the superordinate
goal in the hierarchical condition
 but not the sequential condition

Story grammar structure matters

Strongly support the hypothesis that readers do make
global causal connections during reading.
Discourse in memory

Daily Summary:



Schemas are used to structure comprehension and
memory
Discourses have internal structures that impact
comprehension and memory
Weekly summary:

Evidence supports the psychological reality of a number of
different representations
 Propositions & propositional networks
 Embodied representations
 Inferences
 Schemata and scripts
 Situation models
Discourse in memory

Kintsch’s model


The Construction-Integration Model
Discourse occurs in a series of cycles


In each cycle



As each sentence comes in it gets integrated into the
discourse
Construction phase - activate relevant concepts
Integration phase - keep only the most relevant
elaborations
Multiple levels of representation formed

Surface form, textbase (propositional), situation model
Discourse in memory

Kintsch and colleagues (1990)
It was Friday night and Jack and Melissa were bored, so
they decided to catch a movie. Jack scanned the
newspaper. He saw that they could just make the nine
o’clock showing of the hot new romantic comedy. Off they
went.

Read before
Did this sentence occur in the paragraph?
Jack scanned the newspaper.
Jack looked through the newspaper.
Jack looked through the movie ads.
Jack looked over some editorials.
Discourse in memory

Kintsch’s model
Jack scanned the newspaper.
Surface form
S
N
VP
V
Jack scanned
NP
the
newspaper
Discourse in memory

Kintsch’s model
Jack scanned the newspaper.
Surface
form
Textbase
S
N
VP
Examine
V
Jack
Jack scanned
NP Newspaper
the
newspaper
Discourse in memory

Kintsch’s model
Jack scanned the newspaper.
Surface
formSituational Model
Textbase
S
N
VP
Examine
V
Jack
Jack scanned
NP Newspaper
the
newspaper
Discourse in memory

Kintsch and colleagues (1990)
It was Friday night and Jack and Melissa were bored, so
they decided to catch a movie. Jack scanned the
newspaper. He saw that they could just make the nine
o’clock showing of the hot new romantic comedy. Off they
went.

Read before
Similar meaning
Did this sentence occur in the paragraph?
Jack scanned the newspaper.
Jack looked through the newspaper.
Jack looked through the movie ads.
Jack looked over some editorials.
If Better
memory here
Evidence for
surface form
Discourse in memory

Kintsch and colleagues (1990)
It was Friday night and Jack and Melissa were bored, so
they decided to catch a movie. Jack scanned the
newspaper. He saw that they could just make the nine
o’clock showing of the hot new romantic comedy. Off they
went.

Read before
Adds inference
Did this sentence occur in the paragraph?
Jack scanned the newspaper.
Jack looked through the newspaper.
Jack looked through the movie ads.
Jack looked over some editorials.
Infers which section did he scan.
If Better
memory
here
Evidence for
Strong textbase
Discourse in memory

Kintch and colleagues (1990)
It was Friday night and Jack and Melissa were bored, so
they decided to catch a movie. Jack scanned the
newspaper. He saw that they could just make the nine
o’clock showing of the hot new romantic comedy. Off they
went.

consistent
inconsistent
Did this sentence occur in the paragraph?
Jack scanned the newspaper.
Jack looked through the newspaper.
Jack looked through the movie ads.
Jack looked over some editorials.
Consistent with situation model.
Evidence for
Strong situation model
If Better
memory
here
Discourse in memory
Kintch and colleagues (1990)
1.2
1
Trace strength

0.8
Situational
model
Textbase
0.6
0.4
Surface form
0.2
0
-0.2
0 min
40 min 2 days 4 days
Delay
Summary

Discourse processing is both complex and
flexible


Multiple representations
Processing depends on context