Transcript Situated action

Situated actions as ...
An alternative view of human action
An alternative account of the relation
of plans to situated actions
The user as a resourceful person
Lucy Suchman, 1987
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Anthropologist,
– Philosophy ( Dreyfus)
– Phenomenology (Merleau- Ponty )
– Symbolic Interactionism (Garfinkel, Goffman)
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Interested in producing an adequate base of
descriptions of human practices
– What’s happens when someone does something ?
Suchman’s central concern
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The relation between observable behaviour and the
processes not available to direct observation, that make
behaviour meaningful,
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What constitutes purposeful actions and how is it
understood ?
About the European and
the Trukese navigator
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The European navigator exemplifies the cognitive science
model of purposeful action
The Trukese navigator exemplifies the situated action
perspective
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The view of action exemplified by the European navigator is
being reified in the design of intelligent machines
– The logical form of plans makes them attractive for the
purpose of constructing a computational model of action
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The view that purposeful action is determined by plans, is
deeply rooted in the Western human sciences as the correct
model of the rational actor
Two alternative views of action
i) The planning view
The organization and significance of human action is
located in underlying plans (artificial intelligence)
ii) The situated actions view
The prescriptive significance of intentions for situated
actions is inherently vague (ethnomethodology)
The planning view
 Plans
are prerequisite to and prescribe actions at every
level of detail
 Mutual intelligibility is a matter of reciprocal
recognizability of our plans
 The planning view has to do with :
– The planning model (Miller, Galanter and Pribram, 1960)
– Speech act theory (Searle, 1969 )
– The idea of shared background knowledge as the common
resource that is given (Durkheim, 1938)
The planning model in cognitive science
.
 Plans
are a sequence of actions designed to
accomplish a preconceived end,
 Action is a form of problem solving and are
described in terms of preconditions and their
consequences,
 Goals define the actor’s relationship to the
situation of action,
 The situation is those conditions that obstruct or
advance the actor’s progress toward his/her goal
Searle’s speech act theory :
some initial guidelines for
computational models of communication
 The
hypothesis is that people maintain as part of
their models of the world, symbolic descriptions
of the world models of the people
 Speech
act are regarded as actions whose effects
are primarily on the models that speakers and
hearers maintain of each other
Background knowledge
 Gumperz
shows that an action significance seems
to lie as much in what it presupposes and implies
about its situation
 He questions the view that background
assumptions are part of the actor’s mental state
prior of action
 The background knowledge is not taken for
granted
 Significance depends on a particular context that
is always open-endlessness
 Common sense are resources
According to cognitive science
 The
mind is viewed as an abstractable structure
implementable in any number of possible physical
substrates
– intelligence is only incidentally embodied in the
neurobiology of the human brain,
– what is essential about intelligence can be abstracted
from that particular substrate and embodied in an
unknown range of alternative forms
Artificial Intelligence
 People
act on the basis of symbolic representation,
a kind of cognitive code,
 Cognition
is not just potentially like computation
it literally is computational
 The
view that intelligence is the manipulation of
symbols finds practical implementation both in so
called expert systems and industrial robots
What is a plan ?
 ”[…]
When we speak of a plan the term will refer
to a hierarchy of instructions
 A plan is any hierarchical process in the organism
that can control the order in which a sequence of
operations is to be performed.
 A plan is for an organism essentially the same as a
program for a computer […]” Miller, Galanter and
Pribram, 1960
The situated action view
 Focus
on practice as different to the study of the
formal cognitive properties of artifacts
 Unit of analysis is the activity of persons-acting in
setting
 The prescriptive significance of intentions for
situated action is inherently vague,
 Improvisatory nature of human action
 Human action is contingent
Situated action view

Every course of action depends in essential ways upon its
material and social circumstances
1- Plans are representations of situated actions
2- In the course of situated action representation occurs where
there is a breakdown
3-The objectivity of the situation of our action is achieved rather
than given
4- Central resource for achieving the objectivity of situations is
language
5-Mutual intelligibility is achieved in every occasion of
interaction
The problem of human-machine
communication
 ”Expert
help system”
– a computer-based system attached to a photocopier,
intended to instruct the user
 The
design objective
– to provide timely and relevant information to the user
regarding the operation of the copier
 The
system must recognize the action of the user
The expert help system identifies ...
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the user’s purposes with a job specification and the
specification invokes a associated plan
the plan is ascribed to the user as a basis for interpreting her
actions
the plan is conveyed in the form of instructions for a step-wise
procedure
the design assumes that there is correspondence of the system’s
plan to the user’s purposes that enables the interaction
 Which
are the consequences of taking a statement of
intent and an ascribed plan as grounds for the
interpretation of situated action ?
Troubles for the resourceful user...
Plans and states
instructions
machine
actions
Situated inquiries
Problems of understanding due to the disparity
of their respective resources
The system’s resources
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The machine has access only to a very small
subset of user action
– i.e.Doors being opened and closed, buttons being
pushed, papers trays being filled…
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The machine is watching the user’s actions
through a very small key hole, mapping what it
saw back onto a pre specified template of possible
interpretations
The user’s resources
 Human
interaction succeeds due not simply to the
abilities to construct meaningfulness but to the
possibility of mutually constituting intelligibility
– i.e.Detection and repair of misunderstandings
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Interactive program exploits certain characteristics of
human conversation
Language of interactivity and the dynamics of
computational artifacts obscure enduring asymmetries that
users discover in practice
Speech acts tell us nothing further about the
significance
A : Are you going to be here for ten minutes ?
B: Go ahead and take your break. Take longer if you
want
A: I’ll just be outside on the porch. Call me if you
need me
B: Ok, Don’t worry
(Gumperz, 1982)
 How
B arrives at the right inference ?
Indexicality of language
 Efficiency
of language lies in :
– expressions with conventional meanings
– its relationship to circumstances (conditional
meanings)
– The indexicality of instructions means that an
instruction ’s significance with respect to action does
not inhere in the instruction but must be found in the
situation of use
The mutual intelligibility of actions
 Within
the normative paradigm actors share a
system of culturally established symbols and
meanings
 The
stability of the social world is not due to an
eternal structure but to situated actions that create
and sustain shared understanding on specific
situations of interaction
Relation of plans to situated actions
 In
the planning model of human interaction,
– plans are mental constructs, abstractions over
action, representations of situated actions
 Plans do not take sufficient account of the
situatedness of most social behaviour
 The planning model confuses plans with situated
actions
Alternative account of the relation of
plans to situated actions
 The
foundation of action is not plans but local
interactions with the environment
 The function of plans is to orient or position us, to
exploit some contingencies of our environment
and to avoid others
– plans are weak resources
Critiques
 Confined
to the analysis of actions and operations
 Slightly behaviouristic undercurrent in that it is
the subject’s reaction to the environment that
determines action
 Primacy of the situation
 What constitutes a situation is defined by the
researcher
 Resourceful user or …. ?