Situated Cognition 19

Situated Cognition Intermediate article

Kevin O'Connor, University of Wisconsin, Madison, Wisconsin, USA Arthur M Glenberg, University of Wisconsin, Madison, Wisconsin, USA

CONTENTS Introduction Traditional cognitivism and a Cartesian separation

from the world

Theories of situated cognition maintain that intelli­gent human action has evolved within and is shaped by and adapted to the specific forms of activity within which it occurs, and that cognition must therefore be understood and studied as an aspect of embodied practical activity.

INTRODUCTION

Situated cognition is an evolving interdisciplinary project to describe the relationship between em­bodied agents and the social, semiotic, and material settings of their activity. Contemporary theories of situated cognition have arisen and taken shape largely against the background of traditional cog­nitivist perspectives in psychology and artificial intelligence, which have tended to conceive of cognition in terms of abstract and disembodied reasoning processes taking place in the heads of individuals. While many of the topics addressed within situated cognition - such as the nature of knowledge and cognitive processes, and the rela­tionship between knowledge and intelligent action -are shared with cognitivist approaches, the ways in which these topics are understood and studied diverge fundamentally from cognitivism. Theories of situated cognition maintain that intelligent human action has evolved within and is shaped by and adapted to the specific forms of activity within which it occurs, and that cognition must therefore be understood and studied as an aspect of embodied practical activity. Situated cognition is not just a type of cognition that can be distin­guished from 'non-situated' cognition; rather, the­ories of situated cognition claim that human cognition is inherently situated, and that at­tempting to study cognition apart from the specific settings of activity within which it takes place des­troys the phenomenon being studied.

Situated activity theory Body, environment and social context Cognitive artifacts and distributed cognition

TRADITIONAL COGNITIVISM AND A CARTESIAN SEPARATION FROM THE WORLD

Traditional cognitivist approaches in psychology and artificial intelligence are ultimately based on Cartesian ideas about, on one hand, an objective external world whose character is determinate and independent of human knowledge and con­cerns, and on the other hand, the human mind as a rational instrument that is able to discover and use the principles according to which the external world is structured. Cognitivism has developed these tenets into a number of assumptions about the nature of the mind and its relationship to action. (See Descartes, Rem?; Mind-Body Problem)

First the mind and the world are viewed as fundamentally separate from and impenetrable to one another. The world is taken to have an objective and stable character, and the mind is understood as capable of knowing the world by representing it in explicit and formal symbolic terms.

Second, according to cognitivism, this explicit and formal knowledge about the world underlies and is necessary for action; thus, action can only be properly understood in terms of symbolic mental representations of the world and rules for manipu­lating them. (See Symbol Systems)

Third, mental representations are taken to in­volve abstraction from the particularities of specific situations: the more abstract the representation \s, the more generally applicable it is across situations; thus, greater abstraction is a mark of greater poten­tial for intelligent action.

Fourth, the proper level of explanation for cogni­tion involves descriptions of the processing of ab­stract symbols. Thus, the details of the realization of symbols in the brain are taken to be irrelevant to cognitive explanation: it is on this basis that

20 Situated Cognition

computers, despite their physical differences from the human brain, are understood to provide a po­tential model for human intelligence. Moreover, the body is understood not to be involved in symbol processing in any fundamental way; its role is limited to one of providing input to the cognitive system, through perceptual processes, and output, through motor actions.

The cognitivist analysis of the mind and its rela­tion to action is evident in its view of action as the outcome of a process of problem-solving (e.g. New­ell and Simon, 1972). According to this view, action in the world results from a process involving sev­eral discrete steps. First, a situation in the external world is symbolically represented in the mind as a problem to be solved. The mind then performs rule-based operations on the problem to produce a different symbolic representation - a solution to the problem. This solution then produces some action in the world. Note that the relevant context in the problem-solving process is not the world, but a mental representation of it- the problem- which is, in principle, fully specifiable in terms of formal symbolic structures. Thus, action in the world is caused by underlying cognitive processes. The proper focus of study, then, is not action in the world but rather the underlying knowledge, the mental representations and rules for manipu­lating them, that cause action. (See Problem Solv­ing; Newell, Allen; Simon, Herbert A.)

Influenced by this analysis of action, cognitivists have tended to focus on, and indeed have been quite -successful at modeling, problem-solving in sihtations that lend themselves to description in terms of the manipulation of abstract symbols. Two common types of problem used in cognitivist research can serve to. illustrate this. One type of problem, of which the well-known 'tower of Hanoi' is an example, is intended to provide a window to purportedly general cognitive processes by examining problem-solving in simple abstract situations, which often bear little resemblance to the kinds of activities people pursue in much of their everyday life. Another type of problem is drawn from activities, such as chess, that are chosen because they are suitable for producing formalizable cognitive tasks with clear criteria for determining appropriate solutions.

SITUATED ACTIVITY THEORY

Beginning around the 1980s, a number of theoret­ical and practical difficulties with the cognitivist paradigm, along with empirical observations that were anomalous from the cognitivist point of view,

led researchers to explore alternatives to the trad­itional emphasis on cognition as the purely mental manipulation of abstract symbolic representations. Work in this new perspective, a loose convergence of a variety of anti-Cartesian traditions, placed primary emphasis upon activity situated in its everyday contexts.

Some of this work pointed to a theoretical prob­lem associated with the cognitivist assumption that symbols are manipulated solely on the basis of their abstract form, and suggested that cognitivism provides no account of how symbols ultimately come to take on meaning in human action and experience. The abstract symbols (e.g. nodes in a semantic network) are equivalent to the zeros and ones in a computer. What differentiates one con­cept from another is solely the set of relations among the symbols corresponding to the two con­cepts. Thus, one symbol is defined solely in terms of other symbols. In contrast, Hamad (1990), Searle (1980) and others have argued that meaning (e.g. what concepts are about) cannot, in principle, arise from such a system. For example, Harnad asks us to consider how we could understand a sentence written in a foreign language using only a diction­ary for that language. We would look up in the dictionary the first word in the sentence (the first abstract symbol) and see that it is defined in terms ofrelations to other abstract symbols. On looking up-the first word in the definition, we find only more abstract symbols. Clearly, we will never be fble to discover the meaning of the first word in the sentence, let alone the meaning of the sentence. Yet abstract symbol theory claims just this: that mean­ing arises from the relations among the symbols. If abstract symbols are to be meaningful, they must be grounded in the world through perception and action. But Hilary Putnam has formally proved that starting just from a set of abstract symbols, there is an infinite number of exactly corresponding objects and relations in the world, so it is impossible to ground the abstract symbols under these condi­tions (Lakoff, 1987, pp. 229-259). (See Symbol­grounding Problem; Meaning; Chinese Room Argument, The)

Others have suggested that the cognitivist re­quirement that the world be represented in explicit symbolic terms presents a further theoretical diffi­culty. Among the major practical limitations of the cognitivist tradition is its difficulty in modeling common-sense knowledge. While cognitivism has been very successful at modeling certain kinds of highly formalized cognitive tasks, modeling some very basic forms of everyday human intell­igence has proved to be much more problematic.

Consider, for example, a pedestrian deciding when to cross a street. There is a simple rule: wait for a green crossing light. But this rule needs to be modi­fied to fit almost every conceivable situation: if you are in a great hurry, then cross against the light, except if traHic is extremely heavy, in which case wait, except if it is a real emergency, in which case cross anyway, except if traffic is extremely heavy, in which case wait, except if the traffic is moving slowly, in which case cross, except if you have a twisted ankle, and so on. Some researchers have argued that this practical difficulty is a reflec­tion of the impossibility in principle of explicitly modeling common-sense knowledge (e.g. Dreyfus, 1979). Dreyfus, drawing on phenomenology and the later philosophy of Wittgenstein, takes issue with the cognitivist assumption that explicit sym­bolic representation of the world is necessary to produce action, and argues that action in the every­day world depends on an enormous body of back­ground knowledge, combined with perception of affordances (Gibson, 1979), that is, how a particular type of body constrains actions·occurringftn a par­ticular situation and structured in part by particu­lar goals. Given that the affordances for action will change with momentary changes in bodily abilities (such as adrenaline surges) and with changes in the goals, no set of rules can be constructed to guide actions in situations treated as members of abstract categories such as 'street-crossing situation'. Since all situations are unique, abstract rules cannot be constructed to ensure the adequacy of action in the situation in general. In this view, then, even if the explicit models offered by cognitivism are able to provide insight into certain aspects of cognition, these insights are strictly limited to for­malizable aspects of cognition and do not provide us with a plausible general model of human cogni­tion. (See Phenomenology; Perception: The Eco­logical Approach; Wittgenstein, Ludwig; Gibson, James J.)

These weaknesses and limitations of cognitivism, along with others to be discussed below, have led some researchers to conclude that the com­plexity of the relationship between the mind and its environment is such that considering them separately involves unjustifiable oversimplifica­tion, and that primary analytical emphasis should instead be placed on cognition as it occurs in situ­ated activity. While not all researchers would commit themselves equally to each of the following points, theories of situated cognition have pro­posed several possible alternative assumptions about the nature of cognition and its relationship to action:

Situated Cognition 21

• The mind and the world are fundamentally intercon­nected with one another. The character of the world is not given, but is instead dependent upon construal by agents in the course of activity. These construals, fur­thermore, are both enabled and constrained by the structure of the brain, by the body, and by their occur­rence in specific physical and social contexts.

• Representations of the world are not abstract, disem­bodied, and detached from the world, but arise in the course of situated activity.

• Knowledge is located in the evolving relationships between people and artifacts in culturally evolved systems of activity.

• Cognition is mediated by artifacts and distributed across people in systems of activity.

• Cognition is opportunistic and improvized. Successful participation in everyday activity, rather than engage­ment in tasks based on formal logic, is the primary phenomenon to be explained.

BODY, ENVIRONMENT AND SOCIAL CONTEXT

This shift in focus from abstract and logical think­ing to successful participation in everyday activity has led to a corresponding shift of attention to­wards phenomena that have been considered by cognitivists to be of marginal importance. For example, whereas cognitivism treats sensorimotor processes as peripheral to and separate from the cognitive system, theorists of situated cognition have begun, in various ways, seriously to study the consequences of physical embodiment for the nature of cognitive processing. (See Embodiment)

One area of research has focused on individual cognition, and has attempted to identify universal aspects of cognition that are grounded in the nature of the human body and its capacity to act in a physical environment. This work argues that cog­nitive processes, even symbolic processes, are not abstract and are intimately linked to the embodied nature of the organisms carrying out those pro­cesses. Other researchers emphasize the fact that physical bodies are a part of the physical world in which they act,. and claim that this located~ss requires alternative ways of thinking about cog­nition.

Recent research in cognitive psychology and cog­nitive linguistics, while retaining a primary focus on the cognitive processes of individuals, has at­tempted to understand how cognition has evolved and how it functions in the service of embodied organisms who act in a physical environment. In this work, symbolic mental representations have remained at the center of studies of cognition. However, instead of being viewed as abstract or

22 Situated Cognition

amodal (that is, as bearing only an arbitrary con­nection to experience in the world) symbols are viewed as inherently perceptual in that they mo­dally or analogically replicate some aspect of ex­perience. Thus, this work takes representational units to develop within activity and to remain linked to activity. Lakoff (1987) suggests that even our most abstract concepts -logical rules, such as 'p or q but not both' - arise from experience in the world. For example, our experience with containers and containment provides just the structure for the · rule: something can be in the container (p) or not in the container (q), but not both. Barsalou (1999) has demonstrated that the representations of many concepts have components related to the way the corresponding objects are perceived and acted upon, rather than consisting of amodal abstract symbols. (See Cognitive Linguistics)

Glenberg and Robertson (2000) demonstrate that understanding simple sentences requires a consid­eration of how human actions can combine. Thus, people find sentences such as 'Bill stood ori. the tractor to paint the top of the barn wall' m4ch more sensible than sentences such as 'Bill stood on the hammer to paint the top of the barn wall'. From the point of view of abstract symbols, the two

. sentences are virtually identical: tractors· and hammers are both inanimate concrete nouns; both are tools, and both are unrelated to painting in past experience. The difference is that knowledge of how people can interact with objects- even when used in atypical and never-before-encountered ways- allows people to determine which sentence is sensible and which is nonsense.

Recent work in artificial intelligence and robotics has contributed in a somewhat different way to an understanding of the importance of embodiment for cognition (e.g. Agre and Chapman, 1987; Brooks, 1991). This work has argued that situated activity by embodied agents in a complex physical environment is a nontrivial accomplishment, and one that must be viewed as central to intelligence. However, it has not been modeled successfully by approaches that are grounded in traditional artifi­cial intelligence. Thus, some researchers have at­tempted to design agents that are able to respond effectively, in real time, to the demands of complex, unpredictable, and changing environmental condi­tions. An important strategy has been to replace the traditional cognitivist focus on perception, model­ing, planning and action as discrete steps in a prob­lem-solving process, by proposing a tight coupling of sensing and action. These embodied agents ex­ploit features of the physical environment and their own relationship to it so as to avoid the need to

form a complete and explicit representation of the environment before acting. Instead, they opportun­istically exploit aspects of the structure of the en­vironment that offer clues about how to proceed and when a task has been completed. (See Situated Robotics)

Similar opportunism and context-embeddedness has been demonstrated in research, largely inspired by the cultural-historical tradition begun by L. S. Vygotsky, that examines humans engaged in a wide variety of practical tasks. This work has led Sylvia Scribner to argue that the environment plays a 'con­stitutive role' in cognition. Scribner (1997, p. 329) argues that 'skilled practical thinking incorporates features of the task environment (people, things, information) into the problem-solving system. It is as valid to describe the environment as part of the problem-solving system as it is to observe that prob­lem-solving occurs "in" the environment.' (See Cul­tural Psychology; Vygotsky, Lev)

This work challenges a number of ideas fostered by cognitivist models of problem-solving, includ­ing: that problems are given to the problem-solver in a complete form; that problems of the same logical class will be solved by the same sequence of operations on all occasions; and that learning involves increasing independence from the con­crete particularities of a context. Instead, studies of problem-solving in a wide range of everyday activities have shown that what appear, in theory, to be formally identical problems are, in practice, flexibly formulated and solved by the problem solver according to the contingencies of the envir­onment. For example, Scribner has shown that dairy workers reformulate abstract computational problems into problems that depend on the con­crete physical array of the product they are working with. She has shown, in addition, that these reformulations differ depending on the nature of the activity (e.g. 'filling orders' versus 'inventory'), on the specific point in the flow of activity, and on the values and goals of the prob­lem-solver. Similar claims have been made regarding the skilled practical thinking of shop­pers, cooks, bartenders, street vendors, and partici­pants in a range of other activities.

This work indicates that, compared with novices, experts in a domain of activity rely more, not less, on environmental sources of information. This movement towards increasing contextualization of practical thinking not only contradicts cognitiv­ist claims suggesting that cognition should become more powerful as it becomes less contextualized; it also suggests that cognitivist models of thinking as a purely mental activity will find analysis of many

practical thinking problems intractable (Scribner, 1997). It is also important to note, lest one conclude that the cognition of what Lave (1988) ironically called 'just plain folks' represents an inferior and deficient mode of thought, that the very same kinds of context-embeddedness and opportunism have been demonstrated in careful studies of the work of those who, to cognitivists, represent the height of rationality, such as scientists, mathematicians, en­gineers, and medical diagnosticians (e.g. Goodwin, 1995; Latour, 1987; Norman and Brooks, 1997).

In addition to emphasizing the role of the envir­onment in cognition, work in situated cognition has emphasized that it is necessary to understand sev­eral ways in which the social context influences cognitive processing. One of these is closely related to the opportunism and flexibility of practical prob­lem-solving. When Scribner's dairy workers trans­formed abstract computational problems into problems that were tied to the physical environ­ment in which they were situated, they did so by using materials (e.g. milk crates) designed for non­cognitive purposes (e.g. holding ~ilk b11ttles) to mediate their formulation and solution of a cog­nitive task. This is an instance of a more general capacity of human beings to modify ~!their envir­onment by creating mediating artifacts. These artifacts,. moreover, can transform 'subsequent possibilities for activity by embodying 'partial solutions to frequently encountered problems' (Hutchins, 1995, p. 374) of an individual or group, and can preserve these solutions to be passed on to subsequent generations. In this sense, use of a me­diating artifact situates its user within the cultural tradition that developed, transmitted, and con­tinues to maintain that artifact.

A second, and closely related, way in which the social context is important in cognitive processing is connected with the idea that individual mental functioning has its origins in social interaction. A great deal of research, much of it again building on the ideas of Vygotsky, has demonstrated that social interaction provides the conditions within which skilled practical thinking is mastered by indi­viduals. According to this work, other actors pro­vide the individual with support in performing cognitive tasks that he or she would be unable to perform alone. Through this kind of 'apprentice­ship' (Rogoff, 1990), individuals develop mental structures and processes that can be traced to their origins in social interaction. This is not to claim that forms of individual cognition directly copy processes found in social interaction: indi­viduals transform cognitive structures and pro­cesses in the course of internalization, and

Situated Cognition 23

cognition is opportunistically adapted by agents to their specific circumstances of activity (Wertsch, 1998). (See Culture and Cognitive Development)

Finally, some cognitive tasks are more properly viewed as carried out by social groups than by individuals, so the cognitive processes of indi­viduals engaged in such tasks must be viewed in terms of their relationship to the larger cognitive system.

These points about the importance of the social context for cognitive processing have been of cen­tral importance in recent work on cognitive arti­facts and distributed cognition.

COGNITIVE ARTIFACTS AND DISTRIBUTED COGNITION

Vygotsky's primary concern was with semiotic ar­tifacts, or signs, and the ways in which they medi­ate higher mental functioning in. humans. D. A. Norman, drawing on this emphasis within the cul­tural-historical tradition, introduced the idea of 'cognitive artifacts'. For Norman (1991, p. 17), cog­nitive artifacts are 'those artificial devices that maintain, display, or operate upon information in order to serve a representational function and that affect human cognitive performance'. Examples of cognitive artifacts include language, inscriptional systems for representing language, maps, lists, and calculators.

A well-known example can illustrate the import­ance of cognitive artifacts in mediating cognitive processes (Rumelhart et al., 1986; Wertsch, 1998). Multiplication of multi-digit numbers - for example, multiplying 343 by 822 - represents a highly abstract conceptual problem. However, such a problem can be transformed by first arran­ging the digits in a spatial array and then carrying out a sequence of concrete operations on the digits, as shown in Figure 1.

Here, the spatial array serves as a cognitive artifact that transforms an abstract and difficult

343 822

686 6860

274400

281946

Figure 1. An example of a cognitive artifact. An abstract and difficult problem (multiplying 343 by 822) is trans­formed into a relatively simple one by a process of ar­rangement of the digits and simple operations on them.

24 Situated Cognition

problem into a relatively simple one that most of us become very good at. It is important to note, how­ever, that while an individual problem-solver must have knowledge of how to use this cognitive arti­fact, the knowledge required to solve this problem is not wholly a property of the individual. That is, much of the knowledge required for solving multi-digit multiplication problems is contained in the cognitive artifact, in the form of historically evolved ways of arranging and operating on digits. Moreover, while the cognitive processing involved in solving this problem does involve the manipula­tion of symbols, this symbol manipulation is not likely to be performed solely in the head, but will also depend on the use of materials in the world, such as paper and pencil. Indeed, as Wertsch (1998) points out, many individuals who are able easily to solve problems like this are unaware of the abstract principles involved in the cognitive· artifact, and would in fact be unable to solve the problem if the use of the artifact were not possible- for example, without the use of paper and pencil in a noisy room. 1

Observations of this sort have led some theorists of situated cognition to propose that cognition is 'distributed - stretched over, not divid~d among -mind, body, activity, and culturally organized set­tings (which include other actors)' (Lave·, 1988, p. 1). Theorists of distributed cognition argue that the study of cognition cannot involve only the study of what is in individual heads, but must extend 'beyond the skin' (Hutchins, 1995) to examine how individuals. and groups of individuals use historically evolved artifacts in carrying out their activities. For example, Hutchins' study of the navi­gation team of a large naval vessel shows that, while there is a great deal of computation involved in the navigation of a large ship, this computation does not take place in the head of any individual, but in a coordination of the minds of different individuals with navigational artifacts, such as landmarks, maps, phone circuits, and organiza­tional roles. The cognition of individuals often in­volves little more than what is involved in reading numbers or drawing lines. The symbol processing necessary for navigation is performed by the 'func­tional system' of a collection of individuals acting with cognitive artifacts.

Work in distributed cognition suggests that understanding how cognition is mediated by arti­facts and realized in activity and social interaction leads ultimately to the study of how cognition is tied to and partially constitutive of cultural systems. Proponents of distributed cognition have called for a redefinition of the disciplinary

boundaries of cognitive science, with a much more central role given to such fields as anthropol­ogy, sociology, and cultural psychology, whose methods and interests are well suited to the kinds of detailed 'cognitive ethnography' called for in the study of distributed activity systems.

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Further Reading

Agre PE (1996) Computation and Human Experience. New York, NY: Cambridge University Press.

Bowker GC, Star SL, Turner WL and Gasser L (eds) (1997) Social Science, Technical Systems, and Cooperative Work: Beyond the Great Divide. Mahwah, NJ: Erlbaum.

Clancey WJ (1997) Situated Cognition: On Human Knowledge and Computer Representations. New York, NY: Cambridge University Press.

Clark A (1997) Being There: Putting Brain, Body and World Together Again. Cambridge, MA: MIT Press.

Cole M (1996) Cultural Psychology: A Once and Future Discipline. Cambridge, MA: Harvard Universitp Press.

Cole M, Engestrom Y and Vasquez 0 (eds) (1997) Mind, Culture and Activity: Seminal Papers from the,.Laboratory of Comparative Human Cognition. New York, NY: Cambridge University Press.

Situated Robotics 25

Gee JP (1992) The Social Mind: Language, Ideology, and Social Practice. New York, NY: Bergin and Garvey.

Greeno JG, Chi MTH, Clancey WJ and Elman J (eds) (1993} Cognitive Science 21: 1-147. [Special issue on situated action.]

Kirshner D and Whitson JA (eds) (1997) Situated Cognition: Social, Semiotic, and Psychological Perspectives. Mahwah, NJ: Erlbaum.

Lave J and Wenger E (1991) Situated Learning: Legitimate Peripheral Participation. New York, NY: Cambridge University Press.

Nardi BA (ed.) (1996) Context and Consciousness: Activity Theory and Human-Computer Interaction. Cambridge, MA: MIT Press.

Rosenschein SJ and Kaelbling LP (1995) A situated view of representation and control. Artificial Intelligence 73: 149-173.

Stanfield RA and Zwaan RA (2001) The effect of implied orientation derived from verbal context on picture recognition. Psychological Science 12: 153--156.

Suchman LA (1987) Plans and Situated Actions: The Problem of Human Machine Communication. New York, NY: Cambridge University Press.

Tomasello M (1999} The Cultural Origins of Human Cognition. Cambridge, MA: Harvard University Press.

Vygotsky LS (1978) Mind in Society. Cambridge, MA: Harvard University Press.

Winograd T and Flores F (1986) Understanding Computers and Cognition: A New Foundation for Design. Reading, MA: Addison-Wesley.