David Kirsh

The question of how to conceive and represent the context of work is explored from the theoretical perspective of distributed cognition. It is argued that to understand the office work context we need to go beyond tracking superficial physical attributes such as who or what is where and when and consider the state of digital resources, people’s concepts, task state, social relations, and the local work culture, to name a few. In analyzing an office more deeply, three concepts are especially helpful: entry points, action landscapes, and coordinating mechanisms. An entry point is a structure or cue that represents an invitation to enter an information space or office task. An activity landscape is part mental construct and part physical; it is the space users interactively construct out of the resources they find when trying to accomplish a task. A coordinating mechanism is an artifact, such as a schedule or clock, or an environmental structure such as the layout of papers to be signed, which helps a user manage the complexity of his task. Using these three concepts we can abstract away from many of the surface attributes of work context and define the deep structure of a setting—the invariant structure that many office settings share. A long-term challenge for context-aware computing is to operationalize these analytic concepts.

When people make sense of situations, illustrations, instructions and problems they do more than just think with their heads. They gesture, talk, point, annotate, make notes and so on. What extra do they get from interacting with their environment in this way? To study this fundamental problem, I looked at how people project structure onto geometric drawings, visual proofs, and games like tic tac toe. Two experiments were run to learn more about projection. Projection is a special capacity, similar to perception, but less tied to what is in the environment. Projection, unlike pure imagery, requires external structure to anchor it, but it adds ‘mental’ structure to the external scene much like an augmented reality system adds structure to an outside scene. A person projects when they look at a chessboard and can see where a knight may be moved. Because of the cognitive costs of sustaining and extending projection, humans make some of their projections real. They create structure externally. They move the piece, they talk, point, notate, represent. Much of our interactivity during sense making and problem solving involves a cycle of projecting then creating structure.

In the scientific study of mind a distinction is drawn between explicit knowledge— knowledge that can be elicited from a subject by suitable inquiry or prompting, can be brought to consciousness, and externally expressed in words—and implicit knowledge—knowledge that cannot be elicited, cannot be made directly conscious, and can- not be articulated. Michael Polanyi (1967) argued that we usually ‘know more than we can say’. The part we can articulate is explicitly known; the part we cannot is implicit.

Contemporary choreography offers a window onto creative processes that rely on harnessing the power of sensory sys- tems. Dancers use their body as a thing to think with and their sensory systems as engines to simulate ideas non- propositionally. We report here on an initial analysis of data collected in a lengthy ethnographic study of the making of a dance by a major choreographer and show how translating between different sensory modalities can help dancers and choreographer to be more creative.

Metacognition is associated with planning, monitoring, evaluating and repairing performance Designers of elearning systems can improve the quality of their environments by explicitly structuring the visual and interactive display of learning contexts to facilitate metacognition. Typically page layout, navigational appearance, visual and interactivity design are not viewed as major factors in metacognition. This is because metacognition tends to be interpreted as a process in the head, rather than an interactive one. It is argued here, that cognition and metacognition are part of a continuum and that both are highly interactive. The tenets of this view are explained by reviewing some of the core assumptions of the situated and distribute approach to cognition and then further elaborated by exploring the notions of active vision, visual complexity, affordance landscape and cue structure. The way visual cues are structured and the way interaction is designed can make an important difference in the ease and effectiveness of cognition and metacognition. Documents that make effective use of markers such as headings, callouts, italics can improve students' ability to comprehend documents and 'plan' the way they review and process content. Interaction can be designed to improve 'the proximal zone of planning' - the look ahead and apprehension of what is nearby in activity space that facilitates decisions. This final concept is elaborated in a discussion of how e-newspapers combine effective visual and interactive design to enhance user control over their reading experience.

The type of principles which cognitive engineers need to design better work environments are principles which explain interactivity and distributed cognition: how human agents interact with themselves and others, their work spaces, and the resources and constraints that populate those spaces. A first step in developing these principles is to clarify the fundamental concepts of environment, coordination, and behavioural function. Using simple examples, I review changes the distributed perspective forces on these basic notions.

Video data from three large captures of choreographic dance making was analyzed to determine if there is a difference between participant knowledge – the knowledge an agent acquires by being the cause of an action – and observer knowledge – the knowledge an observer acquires through close attention to someone else’s performance. The idea that there might be no difference has been challenged by recent findings about the action observation network and tacitly challenged by certain tenets in enactive perception. We explored why a choreographer ‘riff’s’ when appropriating and evaluating the movements of his dancers. By recruiting his body to help him cognize he is able to understand the possibilities of movement better than observation. He acquires participant knowledge.

The objective of this essay is to provide the beginning of a principled classification of some of the ways space is intelligently used. Studies of planning have typically focused on the temporal ordering of action, leaving as unaddressed questions of where to lay down instruments, ingredients, work-in-progress, and the like. But, in having a body, we are spatially located creatures: we must always be facing some direction, have only certain objects in view, be within reach of certain others. How we manage the spatial arrangement of items around us is not an afterthought: it is an integral part of the way we think, plan, and behave. The proposed classification has three main categories: spatial arrangements that simplify choice; spatial arrangements that simplify perception; and spatial dynamics that simplify internal computation. The data for such a classification is drawn from videos of cooking, assembly and packing, everyday observations in supermarkets, workshops and playrooms, and experimental studies of subjects playing Tetris, the computer game. This study, therefore, focuses on interactive processes in the medium and short term: on how agents set up their workplace for particular tasks, and how they continuously manage that workplace.

Cognitive organisms have three rather different techniques for intelligently regulating their intake of environmental information. In order of the time needed to uncover information they are: 1. control of attention: within an image produced by a given sensor certain elements can be selected for additional processing; 2. control of gaze: the orientation and resolution (center of foveation) of the sensor can be regulated to create a new image; 3. control of activity: certain non-perceptual actions can be performed to increase the probability of unearthing salient information that currently is unavailable, hard to detect, or hard to compute.

Multimedia technology offers instructional designers an unprecedented opportunity to create richly interactive learning environments. With greater design freedom comes complexity. The standard answer to the problems of too much choice, disorientation, and complex navigation is thought to lie in the way we design interactivity in a system. Unfortunately, the theory of interactivity is at an early state of development. After critiquing the decision cycle model of interaction—the received theory in human computer interaction—I present arguments and observational data to show that humans have several ways of interacting with their environments, which resist accommodation in the decision cycle model. These additional ways of interacting include: preparing the environment, maintaining the environment, and reshaping the cognitive congeniality of the environment. Understanding how these actions simplify the computational complexity of our mental processes is the first step in designing the right sort of resources and scaffolding necessary for tractable learner controlled learning environments.

To explore the question of physical thinking – using the body as an instrument of cognition – we collected extensive video and interview data on the creative process of a noted choreographer and his company as they made a new dance. A striking case of physical thinking is found in the phenomenon of marking. Marking refers to dancing a phrase in a less than complete manner. Dancers mark to save energy. But they also mark to explore the tempo of a phrase, or its movement sequence, or the intention behind it. Because of its representational nature, marking can serve as a vehicle for thought. Importantly, this vehicle is less complex than the version of the same phrase danced ‘full-out’. After providing evidence for distinguishing different types of marking, three ways of understanding marking as a form of thought are considered: marking as a gestural language for encoding aspects of a target movement, marking as a method of priming neural systems involved in the target movement, and marking as a method for improving the precision of mentally projecting aspects of the target.

The objective of research in the foundations of Al is to explore such basic questions as: What is a theory in Al? What are the most abstract assumptions underlying the competing visions of intelligence? What are the basic arguments for and against each assumption? In this essay I discuss five foundational issues: (1) Core Al is the study of conceptualization and should begin with knowledge level theories. (2) Cognition can be studied as a disembodied process without solving the symbol grounding problem. (3) Cognition is nicely described in propositional terms. (4) We can study cognition separately from learning. (5) There is a single architecture underlying virtually all cognition. I explain what each of these implies and present arguments from both outside and inside Al why each has been seen as right or wrong.

Contemporary choreography offers a window onto creative processes that rely on harnessing the power of sensory sys- tems. Dancers use their body as a thing to think with and their sensory systems as engines to simulate ideas non- propositionally. We report here on an initial analysis of data collected in a lengthy ethnographic study of the making of a dance by a major choreographer and show how translating between different sensory modalities can help dancers and choreographer to be more creative.

Mechanisms for QoS provisioning in communication networks range from flow-based resource reservation schemes, providing QoS guarantees, through QoS differentiation based on reservation aggregation techniques to adaptation of applications, compensating for incomplete reservations. Scalable, aggregation-based reservations can also be combined with adaptations for a more flexible and robust overall QoS provisioning. Adaptation is particularly important in wireless networks, where reservations schemes are more difficult to realize. It is widely accepted that usability of Cellular or Mobile IP can be largely improved if adaptation is incorporated. Adaptation, in turn, depends on coding techniques involved and on user requirements. Those impose certain preferences and ordering relations on QoS hierarchies or degradation paths to be followed along when adaptation is performed. With the advent of MPEG4 coding techniques, more sophisticated adaptation schemes are more likely to be supported in the future.

A complementary strategy can be defined as any organizing activity which recruits external elements to reduce cognitive loads. Typical organizing activities include pointing, arranging the position and orientation of nearby objects, writing things down, manipulating counters, rulers or other artifacts that can encode the state of a process or simplify perception. To illustrate the idea of a complementary strategy, a simple experiment was performed in which subjects were asked to determine the dollar value of collections of coins. In the no-hands condition, subjects were not allowed to touch the coin images or to move their hands in any way. In the hands condition, they were allowed to use their hands and fingers however they liked. Significant improvements in time and number of errors were observed when S's used their hands over when they did not. To explain these facts, a brief account of some commonly observed complementary strategies is presented, and an account of their potential benefits to perception, memory and attention.

In the course of daily life we solve problems often enough that there is a special term to characterize the activity and the right to expect a scientific theory to explain its dynamics. The classical view in psychology is that to solve a problem a subject must frame it by creating an internal representation of the problem’s structure, usually called a problem space. This space is an internally generable representation that is mathematically identical to a graph structure with nodes and links. The nodes can be annotated with useful information, and the whole representation can be distributed over internal and external structures such as symbolic notations on paper or diagrams. If the representation is distributed across internal and external structures the subject must be able to keep track of activity in the distributed structure. Problem solving proceeds as the subject works from an initial state in mentally supported space, actively constructing possible solution paths, evaluating them and heuristically choosing the best. Control of this exploratory process is not well understood, as it is not always systematic, but various heuristic search algorithms have been proposed and some experimental support has been provided for them.

A complementary strategy can be defined as any organizing activity which recruits external elements to reduce cognitive loads. Typical organizing activities include pointing, arranging the position and orientation of nearby objects, writing things down, manipulating counters, rulers or other artifacts that can encode the state of a process or simplify perception. To illustrate the idea of a complementary strategy, a simple experiment was performed in which subjects were asked to determine the dollar value of collections of coins. In the no-hands condition, subjects were not allowed to touch the coin images or to move their hands in any way. In the hands condition, they were allowed to use their hands and fingers however they liked. Significant improvements in time and number of errors were observed when S's used their hands over when they did not. To explain these facts, a brief account of some commonly observed complementary strategies is presented, and an account of their potential benefits to perception, memory and attention.

This article addresses three main questions: What causes cognitive overload in the workplace? What analytical framework should be used to understand how agents interact with their work environments? How can environments be restructured to improve the cognitive workflow of agents? Four primary causes of overload are identified: too much tasking and interruption, and inadequate workplace infrastructure to help reduce the need for planning, monitoring, reminding, reclassifying information, etc… The first step in reducing the cognitive impact of these causes is to enrich classical frameworks for understanding work environments, such as Newell and Simon’s notion of a task environment, by recognizing that our actual workplace is a superposition of many specific environments – activity spaces – which we slip between. Each has its own cost structure arising from the tools and resources available, including the cognitive strategies and interpretational frameworks of individual agents. These cognitive factors are significant, affecting how easy or difficult it is to perform an action, such as finding a specific paper in a “mess” desk. A few simple examples show how work environments can be redesigned and how restructuring can alter the cost structure of activity spaces.

We present data and argument to show that in Tetris—a real-time interactive video game—certain cognitive and perceptual problems are more quickly, easily, and reliably solved by performing actions in the world rather than by performing computational actions in the head alone. We have found that some translations and rotations are best understood as being used to implement a plan, or to implement a reaction. To substantiate our position we have implemented a computational laboratory that lets us record keystrokes and game situations, as well as allows us to dynamically create situations. Using the data of over 30 subjects playing 6 games, tachistoscopic tests of some of these subjects, and results from our own successful efforts at building expert systems to play Tetris, we show why knowing how to use one’s environment to enhance speed and robustness are important components in skilled play.

A startling amount of intelligent activity can be controlled without reasoning or thought. By tuning the perceptual system to task relevant properties a creature can cope with relatively sophisticated environments without concepts. There is a limit, however, to how far a creature without concepts can go. Rod Brooks, like many ecologically oriented scientists, argues that the vast majority of intelligent behaviour is concept-free. To evaluate this position I consider what special benefits accrue to concept-using creatures. Concepts are either necessary for certain types of perception, learning, and control, or they make those processes computationally simpler. Once a creature has concepts its capacities are vastly multiplied.