Plans and Situated Actions
From Jsarmi
Contents |
First Edition
Lucy Suchman, New York: Cambridge University Press, 1987
Preface
I will argue that all activity, even the most analytic, is fundamentally concrete and embodied. (p. viii)
- Purposeful actions are inevitably situated actions. By situated actions I mean simply actions taken in the context of particular, concrete circumstances. (One could argue that we all act like the Trukese, however much some of us my talk like Europeans.) (p. ix)
Introduction
- The problem of shared understanding, or mutual intelligibility, has defined the field of social studies for the past hundred years. (...) to understand the mutual intelligibility of action as a mundane, practical accomplishment of members of the society, is, in large measure, the social scientist's problem of subject matter. An account of that accomplishment would constitute an account of the foundation of social order.
Interactive Artifacts
Interaction between people and machines implies mutual intelligibility, or shared understanding, but:
- How do we account for the shared understanding, or mutual intelligibility?
- How there could be mutual intelligibility between people and machine?
==Plans== (And the "planning model") Communication and actions are strictly related: communication involves assumptions about the intelligibility of actions.
There are two main views of action:
- the organization and significance of actions relays on the underlying plans.
- actions depend by local interactions contingent on the actor's particular circumstances.
The planning model draws on three theories: The planning model, Speech act theory, and Shared Background knowledge
The planning model
The planning model in cognitive science treats a plan as a sequence of actions designed to accomplish some preconceived ends. Action is a form of problem solving, where the actor's problem is to find a path from an initial state to a desired goal.
- Plan generation. First programs are robots in an impoverished environment: robots follow the planning and once in while they check their position in the environment. A following program monitors user actions: the program (NOAH) has a network of partially ordered actions: submits an action to the user and monitor the answer. A positive answer means the user understood the instruction. A negative is taken as a request for info. The computer environment is a social one and requires interpretation of the user's actions.
- Interaction and plan recognition. In AI interaction was accomplished by treating other actors as additional variables in the environment. Now the conditions of the environments include other actors. The problem of interaction, in this view, is to recognize the actions of others as the expression of their underlying plans.
- The Status of plans. There is confusion in the literature on how a plan is treated. Sometimes it is a framework for the analysis of action, in order to understand the goals and actions of the actors. Other times they are treated as psychological procedures that directly direct behavior. "A plan is any hierarchical process in the organism that can control the order in which a sequence of operation is to be performed". This is a psychological "process theory"
Speech act
Language is a form of action: language understanding involves an analysis of a speaker's utterances in terms of the plans those utterances serve. the research problem with language understanding is therefore the same as that of the planning model. Ex: A has a goal. The plan involves asking B some info needed to A to reach the goal. A execute the plan, asks B the question. B tries to understand A's plan.
Background Knowledge
What we understand of other's people action depends among other things by assumptions, or by background knowledge. For cognitive science the background of actions is not the world but the knowledge about the world. But representation of the knowledge has turned out to be problematic in AI. Common sense knowledge remains intractable. There are infinite details to consider, they are never enough and they are not ever really taken in consideration at the moment to act. Nevertheless the image of "shared knowledge" as a set of enumerable body of implicit assumption is assumed to be behind every action. But is this assumption correct?
Phenomenological tradition and Garfinkel challenge this position: " a background assumption is generated by the activity of accounting for an action when the premise of the action is called in question. But there is no particular reason to believe that the assumption actually characterizes the actor's metal state prior to the act." Something is taken for granted when it is not problematic. When there are problems, the context provides for a resource to solve the problem.
The problem with cognitive science is the project of substituting definite procedures for vague plans, and representations of the situation of action, for action's actual circumstances.
Suchman shows problems with all three planning models: the planning model itself, speech act theory and background knowledge.
Situated Actions
Recent efforts within anthropology and sociology challenge the traditional assumption regarding purposeful action and shared understanding.
A new branch of sociology, called ethnomethology, considers practical reasoning about action as a subject matter of social studies, something to be investigated. That means something created by people. Previous theory believed that plans were scientific models of actions and sociology objective was to to improve these models and to transform them in axiomatic theory of actions.
"Situated actions": every course of action depends in essential way upon its material and social circumstances. Rather then abstracting action away from its circumstances and represent it as a rational plan, the approach is to study how people use their circumstances to achieve intelligent action. How do people produce and find evidence for plans in the course of situated action
Plans are representation of actions
There are two views of actions:
1- The actor makes a choice among alternative courses of action, based upon an anticipated consequences of outcome. The action course is just the playing out of these antecedent factors. Accounts of the action taken are just a report on the choices made.
2- Plans are resources for situated actions but do not in any strong sense determine its course. Plans presuppose the embodied practice and changing circumstances of situated actions. Plans do not represent those practice and circumstances in all of their concrete details. Plans are then used also afterwards: we can perform a post hoc analysis of situated action that will make it appear to have followed a rational plan. Rationality anticipates actions before the fact, and reconstruct it afterwards.
Representation and breakdown
When the action is proceeding smoothly it is essentially transparent to us, even if we can always construct rational accounts before and after. The equipment also tend to disappear when it is "ready-to-hand" according to Heidegger terms.
When there is a breakdown, possibly with the equipment, inspection and practical problem solving occurs. In such times our use of the equipment becomes explicitly manifest as a goal-oriented activity, and we may try to formulate rules or procedures (if-then).
Breakdowns also happen when the equipment is unfamiliar.
So, the action is transparent to us and only when there is a breakdown we explicate rules and procedure for the situation that has now become noticeable. In these cases rules are explicated for the purposes of deliberation; and the action, which is otherwise neither rule based nor procedural, is then made accountable to them.
The practical objectivity of situations
Social studies in the early century stated that there is an objective world of social facts, or received norms, and people's attitudes and actions are a response to those. Sociology's fundamental principle is the objective reality of social facts. People responds to two types of rules: environment and sociological. With this assumption sociology could have been considered a science: men respond to social facts, so it is scientific to study these responses.
Ethnometodology instead assumes that our everyday social practices render the world publicly available and mutually intelligible. Ethnometodology studies how common sense is used by people to make sense of the world, which methods do the member of society uses to make sense of talk and actions.
Ethnomethodology is interested in how the mutual intelligibility and objectivity of social world is achieved. It locates this achievement in situated actions: our common sense of the world is the product of social world, not the precondition.
The indexicality of language
Language: 1-expression have assigned to them conventional meaning 2-in some occasions the significance of expressions lies in its relationship to circumstances.
Indexical expressions: expressions that rely upon their situation for significance.
Language is a form of situated action: expression and interpretation involve an active process of pointing to and searching the situation of talk.
Even if some expression are indexical in respect to others, the communicative significance of a linguistic expression is always dependent on the circumstances of its use.
It is impossible to enumerate the list of the circumstances since every utterance's situation comprises an indefinite range of relevant circumstances. There is no finite set of assumptions that underlines a given statement.
The problem of language reflect itself in the instructions: the indexicality of instruction means that the meaning does not inhere in the instruction, but must be found by the instruction follower with reference to the situation of its use. Instruction necessary rely upon an implicit cetera clause in order to be call complete (they cannot ever be complete.)
The mutual intelligibility of action
Language is indexed. Not only. Language participate in the action, it constitutes the situation of its use.
One step further for ethnomethodology: the purposefulness of action is is recognizable in virtue of the methodic, skillful practices whereby we establish the rational properties of actions in particular context.
Garfinkel proposes that the stability of the social world is not the consequence of a "cognitive consensus", or a stable body of shared meanings, but of our tacit use of the documentary method of interpretation to find the coherence of situations and actions. As a general process, the documentary method describes a search for uniformities that underlie unique appearances. In the social world it describes the process whereby actions are taken as evidence of underlying plans or intent, which in turn fill in the sense of actions.
Given the lack of universal rules for the interpretation of action, the program of ethnomethodology is to investigate and describe the use of the documentary method in particular situations. It is to look for the processed whereby particular uniquely constituted circumstances are systematically interpreted so as to render meaning shared and action accountably rational.
Communicative Resources
Action interpretation is inherently uncertain: nonetheless action description is sufficient for its task. People are engaged in the everyday business of making sense of each other actions.
Which ones are the resources that people uses to manage the inherently uncertainty?
For social science these resources are not only cognitive but interactional: interpreting the significance of action is an essentially collaborative achievement. Mutually intellegibility turns on the availability of communicative resources to detect, remedy, and even exploit the inevitable uncertainties of action's significance.
Conversation as "ensemble" work
Speakers and listeners during a conversation do not engage in an alternating sequence of action and response.
Conversation is more a joint action accomplished through the participants' continuous engagement in speaking and listening: listener gives clues and speaker reacts to these clues.
The contextualization cues consist in organization of speech prosody, body position and gesture, gaze, and collaboratively accomplished timing.
Conversational organization
As the basic system for situated communication, conversation is characterized by:
1-an organization design to support local control over the development of topics or activities, and to maximize accommodation to unforseeeable circumstances that arise 2-resources for locating and remedying the communication's troubles
Local Control The organization of conversation maximize local control over the distribution of turns and the direction of subject matter. That is, who talks and what get talked about is decided then and there, by the participant, through their collaborative construction of the conversation's course.
The turn taking is a collaborative achievement, rather than a simple alternation of intrinsically bounded segment of talk. The turn is not something that can be first defined and than examined for how it is passed back and for.
Sequential organization and coherence In general, a coherent conversation is one in which each thing said can be heard relevant to what has come before. The adjacency need not to be immediate. There may be other sentences in between or it can come after some considerable time. An embedding of turns.
The expectations between what is said and what is believed to be an appropriate answer, control the inference about the conversation's content: the answer, lack of it or difference from what is expect help in building the meaning.
Sometimes answers that are not tied to the previous questions are interpreted nonetheless as relevant to the previous utterance. The overall coherence of a conversation is accomplished through the development and elaboration of a local coherence.
Locating and remedying communicative trouble
Communication takes place in real environment and is vulnerable to internal and external troubles.
Our communication succeed in face of these troubles not because we predict reliably what will happen and thereby avoid problems, but we work, moment by moment, to identify and remedy the inevitable troubles that arise.
In addition to control the turn taking, participants must be able to alert alert of possible problems or misunderstanding. Sometimes even when problems are detected participants may want to leave them there. But if problems are not detected until is to late, in certain cases you have failure of communication.
Specialized forms of interaction
There are many cases where the organization of turns and the subject matter are prescribed (by institutions for example.)
Preallocation of turn types: courtroom or communication doctor patient. Even in these cases, even if turn taking is subject to rules, still participant apply those rules in such a way to convey their meaning, or to make sense of it. So are still in a situated way.
Agendas: various setting comprise prescription also for the subject of the communication. For example doctor-patient or counselor-patient talk. Even in these cases the coherence of the talk is not guarantee by the agenda but is achieved moment by moment as a local, collaborative accomplishment.
Face to face interaction is a systems that has evolved to provide an orderly, concerted action. It masters its constraints and leaves open questions of control and direction, while providing mechanism for recovery from trouble and error.
Case and methods
Human-machine communication
The purpose of this chapter is to consider communication between a person and a machine in terms of the nature of their respective situations. The situation of action is the full range of resources that the actor has available to convey the significance of her own actions and to interpret the actions of others.
Engineering an appropriate response
The designer problem is to ensure that the machine responds appropriately to the user's actions. There are two possible approaches: 1-participants anticipate each other's actions 2-participants respond to occasioned and unanticipated actions of the other.
Expert systems use the first approach, building a model of the user and taking his goal as an ascribed plan to interpret his actions.
The system's situation: plans and detectable states System resources for constructing the action of the users: plans and states. Not all user actions are available to the system. Also the history of the action is not available. If a user undo a step, the system keeps no track, it only checks the current status and the position in the plan.
The user's resources: the situated inquiry Problems posed for the designer by the user's principal resource.
If the user follows the plan suggested by the expert system, the system may anticipate the user question "what next" meaning what is the next instruction. But when the "What next" is a matter of repair or abandonment of the plan, then problems occur. The request is for remedy of the current trouble. As a consequence that the situation of the inquiry is not what the system anticipates, the answer that the system offer is inappropriate.
Sometimes the system advances a response for the motivation of an action, but the user is interested in identifying the object of the action. In some occasion the system anticipate "what is the object" but the user wants to know "How to do the action".
While instructions can answer questions about objects and actions, they also pose problems of interpretation that are solved in and through the objects and actions to which the instructions refer.
The user brings the description that the system provides to bear on the material circumstances of her situation, and brings those circumstances to bear on her interpretation of the descriptions.
Conditional relevance of response Problems posed for the designer by the user's ability to find the relevance of the systems' responses to the users' inquiries.
Both user and designer share the expectation that the relevance of each utterance is conditional on the last; that given an action by one party that calls for an answer. If the answer is not an answer, the user will try to interpret it as an answer anyway.
Given some instruction to which the user respond with an action, the user has the following expectations with respect to the system's response: 1-the system response is a new instruction, so the that confirm the adequacy of the user action 2-If the system does not respond, the user action is incomplete 3-If the system respond to repeat an instruction, either the action must be repeated, or there is some trouble in the previous action.
Communicative breakdowns
The false alarm:
a misconception on the user's part leads her to find evidence of an error in her actions where none exist.
Garden Path:
a misconception on the user's part produces an error in her action, the presence of which is masked. At the point where the trouble is discovered by the user, its source is difficult or impossible to reconstruct.
In neither case is the breakdown available as such to the system.
Conclusion
She proposes an alternative view to the cognitive science view of action.
Cognitive: abstract structural account as the ideal representation of actions.
Recent developments in social sciences proposes not to produce formal models of knowledge and action, but to explore the relationship of knowledge and action to the particular circumstances in which acting occur. This view presupposes:
1-the contingence of action on a complex world is an essential resource that makes knowledge possible. 2-to ground theories of action on empirical evidence 3-the organization of action is an emergent property of moment by moment interaction between actors, and between actors and their environment.
Her goal is to describe human-machine communication. She bases her study on studies of human conversation: she applies the insight gained from face to face human communication to human computer communication: it is a special case of human communication in which the resources available to participants are limited.
The limitness of resource imposes the following problems: 1-extenting the access of the machine to the actions and circumstances of the users. 2-make clear to the user the limit of the machine 3-find ways to compensate for the machine's lack of access to the user situation.
In recent efforts, the most common way to solve problem 1-, the limit to user and its circumstances, has been dealt with the introduction of a user model.
Plans are a representation of action. They don't control action but they are a resource (like a map). The action is in the interaction of representation and represented.
Theoretically, understanding the limits of machine behavior could contribute to an account of situated human action and shared understanding (in the same way that AI contributes to the theory of mind.)
Follow-up: Reading and Writing (Journal of the Learning Sciences)
Second Edition: Human-Machine Reconfigurations
Human-Machine Reconfigurations: Plans and Situated Actions, 2nd Edition, Cambridge University Press, 2007
Preface
Suchman presents a series of vignettes as a sort of "extended epigraph" in order to "frame" the book and introduce its themes:
- The irreducibility of lived practice, embodied and enacted
- The value of empirical investigation over categorical debate
- The displacement of reason from a position of supremacy to one among many ways of knowing in acting
- The heterogeneous sociomateriality and real-time contingency of performance
- The new agencies and accountabilities effected through reconfigured relations of human and machine
(p. xii)
Introduction
- The question for this book shifts from one of whether humans and machines are the same or different to how and when the categories of human or machine become relevant, how relations of sameness and difference between them are enacted on particular ocassions, and with what discursive material consequences. (p. 2)
- Almost two decades after the publication of the original text, and across a plethora of subsequent projects in artificial intelligence (AI) and human-computer interaction (HCI), the questions that animated my argument are as compelling, and I believe as relevant, as ever. My starting point in this volume is a critical reflection on my previous position in the debate, in light of what has happened since. (p. 2)
- The turn to so-called situated computing notwithstanding, the basic problems identified previously -briefly, the ways in which prescriptive representations presuppose contingent forms of action that they cannot fully specify, and the implications of that for the design of intelligent, interactive interfaces - continue to haunt contemporary projects in the design of the "smart" machine. (p.3)
Readings and Responses
- I took as my focus the question of interactivity and assumptions about human conversation within the field of AI, working those against the findings that were emerging in sociological studies of face-to-face human conversation. The main observation of the latter was that human conversation does not follow the kind of message-passing or exchange model that formal, mathematical theories of communication posit. Rather, humans dynamically coconstruct the mutual intellegibility of a conversation through an extraordinarily rich set of embodied interactional competencies, strongly situated in the circumstances at hand (the bounds and relevance of which are, in turn, being constituted through that same interaction). (p. 10)
- Suchman noticed that when observing users she, herself, as a competent interactant could often identify their troubles with the machine. She then asked herself how could it be so, and discovered that "the machine could only perceive that small subset of the users' actions that actually changed its state... it was as if the machine were tracking the user's actions through a very small keyhole and them mapping what it saw back onto a prespecified template of possible interpretations (p. 11)
- The results of this analysis was a renewed appreciation for some important differences - more particularly asymmetries - between humans and machines as interactional partners and for the profound difficulty of the problem of interactive interface design. (...) My analysis, in sum, located the problem of human-machine communication in continued and deep asymmetries between person and machine. (p.11)
- The expert help system offered to solved the user's troubles with the machine seemed to have worked, Suchman notes, but for very peculiar reasons: "it exploits certain characteristics of human conversation in ways that encourage attributions of interactivity to machines by their human interlocutors. At the same time, those attributions belie the profoundly different relations of person and machine to the unfolding situation and their associated capacities to interact within and through it. So the machine's users will read instructions offered by an expert help system as comments on the activity underway that should be intelligible, a strategy that proves extremely powerful for moving things along. (p. 12)
Human interaction succeeds to the extent that it does, however, due not simply to the abilities of any one participant to construct meaningfulness but also to the possibility of mutually constituting intelligibility, in and through the interaction. This includes, crucially, the detection and repair of miss- (or different) understandings. And the latter in particular, I argued, requires the kind of presence to the unfolding situation of interaction not available to the machine. (p. 12)
- (
Note Suchman's use of Schegloff's definition of Interactivity. )
- My observation continues to be that although the language of interactivity and the dynamics of computational artifacts obscure enduring asymmetries of person and machine, people inevitably rediscover those differences in practice (p.13)
- The prevailing view within AI in the early to mid-1980s was that the relation of plans to actions was a determining one.' Suchman states that the central text presenting this perspective is Miller, Galanter and Pribram (1960) which is quoted extensively in the Plans chapter of the 1st. edition (p. 36-37): A plan is a hierarchical process in the organism that can control the order in which a sequence of operations is to be performed...we shall say that a creature is executing a particular Plan when in fact that Plan is controlling the sequence of operations he is carrying out. (p.17, original emphasis). A starting premise of my argument was that planning is itself a form of situated activity that results in projections that bear some interesting, and as yet unexplicated, relation to the actions that they project in.
- Notions of Situated
-
- -Brooks in particular embraces an idea of situated action as part of his campaign against representationalism in AI and within a broader argument for an evolutionarily inspired model of intelligence. For Brooks, situated means that creatures reflect their design and adaptation to particular environments (p. 15) [SITUATED = NON REPRESENTATIONAL]
- -(For) Vera (2003) situated comes, in an ironic twist, to mean "predetermined," a sense antithetical to the orientation toward the flexible, ongoing (re-)production of intelligible action that I would take it to convey. (...) My use of situated does not mean acting in the absence of culturally and historically constituted resources for meaning making. On the contrary, as I have reiterated, situatedness is presupposed by such practices and the condition of possibility for their realization. Behavior is not simply "reactive and contingent on the external world" (ibid 283) but rather is relfexively constitutive of the world's significance, which in turn gives behavior its sense. (p.15)
- -Vera and Simon argue that "the central claim of hard SA is that "behavior can only be understood in the context of complex real-world situations. (...) Suchman proposes a rewording that "would make it closer to a claim to which (she) would in fact subscribe, namely "that behavior can only be understood in its relations with real-world situations"
- - Situated vs Planned as two different kinds of action. Situated = spontaneous or improvisational. Set in opposition to predetermining conditions, this leads to an interpretation of situated as involving a kind of erasure of context, as implying that action happens de novo, without references to prior histories. This is of course antithetical to the kind of strong orientation to the circumstances of action that my use of the term was meant to support (...). To my understanding, ethnomethodology's inisistence on the "just here, just now" achievement of social order is not aimed at an erasure of history. Rather, it is a move away from the structuralist premise that prior conditions fully specify what it means to act within the prescripts that institutionalized society provides. As in the analysis of prescriptive representations more broadly, social institutions and the rules that they imply do not reproduce themselves apart from ongoing activity. And like instructions, plans, and other forms of prescriptive representation, both institutions and rules of conduct presuppose in situ forms of social action that they can never fully specify. (p.16)
- -
- (...) I wanted to suggest that plans are just one among many types of discursive artifacts through which we achieve the rational accountability of action. As such they arise through activity and are incorporated into the activities that they project. (...) I had hoped to direct attention (...) to the relation between the activity of planning and the conduct of actions-according to plan. My aim was not to define that relation but to pose it as a question for our collective research agendas and to suggest that ethnomethodology had some crucial contributions toward an answer. (p. 21)
- Interaction as Emanuel Schegloff reminds us (1982) is not the stage on which the exchange of messages takes place, or the means through which intentionality and interpretation operationalize themselves. Rather, interaction is a name for the ongoing, contingent co-production of a shared social/material world. Interactivity as engaged participation with others cannot be stipulated in advance but requires an autobigraphy, a presence, and a projected future. In this strong sense, I would argue, we have yet to realize the creation of an interactive machine. (p.23)
