Making ubiquitous computing available
Vivienne Waller, Robert B. Johnston · Communications of the ACM · 2009
Introduction The field of ubiquitous computing was inspired by Mark Weiser's vision of computing artifacts that disappear. "They weave themselves into the fabric of everyday life until they are indistinguishable from it." Although Weiser cautioned that achieving the vision of ubiquitous computing would require a new way of thinking about computers, that takes into account the natural human environment, to date no one has articulated this new way of thinking. Here, we address this gap, making the argument that ubiquitous computing artifacts need to be physically and cognitively available. We show what this means in practice, translating our conceptual findings into principles for design. Examples and a specific application scenario show how ubiquitous computing that depends on these principles is both physically and cognitively available, seamlessly supporting living. The term 'ubiquitous computing' has been used broadly to include pervasive or context-aware computing, anytime-anywhere computing (access to the same information everywhere) and even mobile computing. Work on this 'ubiquitous computing' has been largely application driven, reporting on technical developments and new applications for RF(Radio Frequency) ID technologies, smart phones, active sensors, and wearable computing. The risk is that in focusing on the technical capabilities, the end result is a host of advanced applications that bear little resemblance to Weiser's original vision. This is a classic case of not seeing the forest for the trees. In this article, we want to take a walk in the forest, that is, to suggest a new way of thinking about how computing artifacts can assist us in living. In doing this, we draw on German philosopher Martin Heidegger's analysis of the need for equipment to be 'available.' While several influential studies in human-computer interaction (HCI) have also drawn on Heidegger and the concept of availability, these studies have focused on physical availability. While going some way to identifying and addressing the problems that Weiser identified with traditional computing, they have not gone far enough. Delving deeper into Heidegger's analysis, we can explain why artifacts designed using the traditional model of computing tend to get in the way of what we want to do. This leads us to refine the concept of physical availability and identify the need for computing artifacts to also be cognitively available. We will first draw on Heidegger to explain why it is that computing artifacts designed according to the traditional model are often a hindrance rather than a help. The traditional conception of how we use computing is based on a particular understanding of human action, which we have referred to elsewhere as the deliberative theory of action. According to this deliberative theory of action, humans reflect on the world before acting. Traditionally computing artifacts are designed to assist us through providing a representation of the world which we can reflect on before action. In other words, the traditional computing artifact requires us to move away from acting in the world to 'use' the computer. In the case of the desktop computer, there is an obvious physical move away from acting in the world to 'using' the computer. Mobile technology can bring the computer to the person in the form of laptops, handhelds and so on. However, as Figure 1 illustrates, mobility, in and of itself, does nothing to remove the dichotomy between reflecting on the world and acting in the world. We consider that Heidegger's account of how we act in the world is a truer account of everyday activity than the deliberative theory of action implicit in Figure 1. According to Heidegger's situated theory of action, we are already thrown into the world, continually responding to the situations we encounter. This means that in everyday activity we seldom achieve the level of detachment that allows us to make reflective decisions before we act. Suchman implicitly draws on Heidegger to argue that, because we are absorbed in coping with the present, we do not have time to form a mental model about how to use technology. This analysis has strongly influenced HCI; however, it does not fully address the problems with the traditional model of computing. In order to articulate a model of computing appropriate for the task of achieving Weiser's vision of ubiquitous computing, we must probe further into the situated nature of action and draw explicitly on Heidegger's characterization of equipment that is available. (The original term 'zuhandenheit' is sometimes translated as ready to hand.) Heidegger describes as available that equipment which helps us to deal with the present without interrupting the flow of absorbed coping. Equipment that is available disappears from our awareness. It is only when the equipment doesn't work as expected that it is noticed. Heidegger gives the example of a hammer that is too heavy for the task of nailing a piece of wood. In this case, the user's attention is drawn away from the task and to the hammer itself; in particular, to the fact that the hammer is too heavy. Because the hammer is no longer available, the user has to find another hammer or find some unfamiliar way of using this heavy hammer before they can proceed with the task of nailing a piece of wood. Whether equipment is available or not depends on a combination of the design and location of the equipment, the user's familiarity with it and what they want to use it for; in other words, the term "available" describes a relationship between the equipment, the user and the task. Although availability requires physical proximity to the user, it is much more than this. Equipment that is available as we use it allows us to focus on what we want to do. This is in contrast to equipment that gets in the way of what we want to do, so that we have to deal with the equipment first. When the activity involves the need to know about something, for example, knowing what to do next, then a new aspect of availability is involved. Whereas physical availability depends on a combination of the physical design and location of the equipment, the user's familiarity with it and what they want to use it for, cognitive availability depends also on the amount of interpretation required to use the equipment. This is trivial in the case of a hammer, but not so in the case of computing artifacts. In order for computing artifacts to support our focus on what we want to do, they need to be both physically available and cognitively available. As the following discussion shows, those within HCI have recognized that the level of availability of the traditional computer is a problem that needs to be addressed. However, because no distinction has been made between physical and cognitive availability, the proposed solutions do not adequately address the issue of designing to improve cognitive availability. Both Weiser and Norman have criticized the design of the traditional computer as getting in the way of acting in the world. Weiser says that the traditional computer "fails to get out of the way of work… Rather than being a tool through which we work, and so which disappears from our awareness, the computer too often remains the focus of attention." As Norman comments in his book The Invisible Computer , 'I don't want to use a computer, I want to accomplish something.' Norman's focus, and that of HCI in general, is on physical availability and how the physical availability of artifacts can be increased through exploiting physical affordances in the design of the computing artefact. Exploiting physical affordances goes some way to increasing cognitive availability, but it does not go far enough. Furthermore, approaches under the rubric of 'ubiquitous computing' have generally also failed to address the issue of improving cognitive availability. For example, 'anytime anywhere' computing is a literal translation of ubiquitous computing, emphasizing access to the same information everywhere, whether by computers located everywhere or users carrying a mobile device. It is basically the traditional model of computing on a grand scale. Lyytinen and Yoo consider that the problem with anytime, anywhere computing is that the computing model does not update as we move location. In their work on pervasive computing, they suggest that the way to make the computer invisible is for the computer to automatically update its model of the world from information it obtains from the environment in which it is embedded. However, although this overcomes the need for unnecessary data entry, it still does nothing to increase cognitive availability. A computing artifact is still not available if we have to turn our attention away from what we are doing to using the computing artifact. In particular, having to interpret a model of the world is disruptive to the flow of situated action. It takes the user's attention away from what they are doing to a model