Transcript Grounding in Communication

Grounding in Communication
Herbert H. Clark
and
Susan E. Brennan
Foreword:
On analyzing conversation
• Real spoken conversation is very messy
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incomplete sentences
overlapping turns
pauses
noisy voice data / unintelligible utterances
• Clark uses some standard notation for
analyzing conversation
– write out what was said, not good English
– pauses in conversation: . , - [2 seconds]
Grounding in Conversation
• In order to have an effective conversation,
the participants need to understand each
other
• To do this they need to ground their
communication
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Listener has to notice that something was said
Listener has to hear what was said
Listener has to understand what was said
Listener has to understand what was meant
Grounding in Conversation
• So what is grounding?
– Making sure that the listener understand what the
speaker said
– Making sure the speaker knows the listener understood
– Making sure the listener knows the speaker knows the
listener understood, etc.
So then what is common ground?
• Information that participants know that they
all know:
– Common cultural and social history
– Public history of the interaction
– Current public state of the interaction
• Common ground accumulates as the
interaction continues
Evidence in Grounding
• Speakers attempt to make sure they were
understood by listeners
• To do this, they look for evidence of
understanding
• Speakers can look for both positive and negative
evidence
Negative feedback
• Usually involves a new communicative
action on the part of the listener
– repetition
• "- have a car?"
– fill-in-the-blank
• "have a what?"
– asking questions or for clarification
– many other methods
Positive feedback
• continuers: *yeah*, mmhm, etc.
• relevant next turns: i.e., something that
makes sense in context and continues the
conversation
Miss Dimple: "Where can I get a hold of you?"
Chico: "I don't know lady. You see, I'm very ticklish."
• continued attention
– Similar to continuants
– But this can sometimes be hard to detect
• HELLO! ANYONE AWAKE OUT THERE?
But... Why don't people just
say what they mean?
• Principle of Least Collaborative Effort
– Basically, people seem to minimize the amount
of effort they have to put out to achieve
understanding
A: That tree has, uh, uh
B: Tent worms.
A: Yeah.
B: Yeah.
– But why?
• Time pressure
• Errors
• Ignorance
Grounding Changes With Purpose
• Participants alter their grounding methods
according to situation and content
– Alternative descriptions
• Adding more detail to ensure grounding
– Indicative gestures
• Pointing, other gestures
– Referential installments
• Breaking a description into understandable chunks
– Trial references
• Speaker puts out a tentative reference; listener
ratifies or rejects it
Grounding verbatim content
• For complex content, participants have
many strategies to ensure error-free
communication
– Verbatim displays
A: "Waltham, MA, 02454"
B: "0-2-4-5-4"
A: "That's right."
– Installments
123…45…6789
– Spelling
Feinman, that's F-e-i-n-m-a-n
Grounding in different media
• So how is this applicable to HCI?
– Users of groupware systems will need to stay
grounded
– Constructing systems to support this grounding
requires understanding how users operate
– Different media that you provide will affect
how users stay grounded
• Clark identifies features of communication
and relates how they affect grounding
Clark's features of communication
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Copresence
Visibility
Audibility
Cotemporality
Simultaneity
Sequentiality
Reviewability
Revisability
Clark's features of communication
• Copresence
– Users are near each other, and can point at
objects in common ground
• Visibility
– Users can see each other; allows gestures, facial
expressions
• Audibility
– Users can hear each other, and use natural
language
• Cotemporality
– Users can expect to receive a timely reply;
interruptions or delays are significant
Clark's features of communication
• Simultaneity
– Users can send and receive at the same time;
allows interruption, backchannel feedback
• Sequentiality
– User contributions are strictly ordered, and
cannot get out of order
• Reviewability
– Users can look at the past history of the
conversation
• Revisability
– Users have the option of editing their
contributions before they commit to them
Some examples
• Face-to-face
– Copresence, visibility, audibility, Cotemporality,
simultaneity, sequentiality
• Telephone / Voice over IP
– Audibility, cotemporality, simultaneity, sequentiality
• Family radio / DirectConnect / walkie-talkies
– Audibility, cotemporality, sequentiality
• Email/SMS/Text messaging
– Reviewability, revisability
• Chat/IM/IRC/ICQ
– Cotemporality, reviewability, revisability
Costs of Grounding
• Different features affect cost for speaker and
listener to ground communication
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Cost of formulation (deciding what to say)
Cost of production (saying it)
Cost of reception (hearing it)
Cost of understanding (understanding it)
Cost of start-up (starting a conversation)
Cost of delay (what impact a delay has)
Cost of asynchrony (what impact misordering has)
Cost of speaker change or multiple speakers
Cost of display / pointing / graphical input
Cost of errors (in production or in understanding)
Cost of repairs
A made up example: face-to-face
Student: I'm having trouble with my code.
TA: Let me see… [looks at window full of code]
Student: It doesn't compile, I think it
TA: Did you include stdio dot h? [looks at student]
Student: include what?
TA: stdio.h . If you use printf or anything you need to include
Student: um, [fidgets]
TA: no, I don't see it there. You'll need to write
Student: yeah [nods, moves to keyboard]
TA: pound . err . sharp - shift-three - include angle bracket stdio.h
angle bracket
Student: ok [starts typing]
Now, in a chat room instead
Student: I'm having trouble with my code.
TA: Let me see…paste it in here
Student: ok [pastes the code]
TA: what's the problem? [copies and compiles the code]
Student: it won't compile
TA: looks like you need to include stdio.h
TA: like this: #include <stdio.h>
Student: ok
TA: because you're using printf
TA: does that make sense?
Student: yeah, I think so. We talked about that in class.
Comparison:
face-to-face v. chat
• Easier to point
• Easier to discuss
• Easier to gauge
understanding
• …
• Easier to produce
complicated content
• Easier to review
history of conversation
• …
Conclusions
• Grounding is essential to communication
• Communication is a collaborative activity
• Content affects grounding
• Medium affects grounding