Mark Weiser on Ubicomp

Posted: December 31st, 2005 | No Comments »

Finishing of the year with some quick Mark Weiser re-readings including Some Computer Science Issues in Ubiquitous Computing, The World is Not A Desktop and Creating the Invisible Interface (Invited Talk). I stumbled on his definition of phase I of ubicomp (phase in which we are very much still in). I should definitively use it to describe that we have not achieved invisibility yet, because technology fails us (and maybe will always do) due to physical, economical, or psychological constraints and limitations. Then he mentions the merit of bits/sec/meter3 that should be used in wireless networking. I might want to try to use it to describe connectivity in my experiments.:

Definition of ubiquitous computing

Ubiquitous computing is the method of enhancing computer use by making many computer available throughout the physical environment, but making them effectively invisible to the user.

Phase I

Phase I of ubiquitous computing: to construct, deploy, and learn from a computing environment consisting of tabs, pads, and borads. This is only phase I, because it is unlikely to achieve optimal invisibility. (Later phases are yet to be determined). [...] As we start to put tabs, pads, and boards into use, phase I of ubiquitous computing should enter its most productive period. With this substrate in place we can make much more progress both in evaluating our technologies and in choosing our next steps.


A good tool is an invisible tool. By invisible, I man that the tool does not introde on the consciousness; you focus on the task, not the tool. Eyeglasses are the good tool – you look at the world, not the eyeglasses. Good tools enhance invisibility. Unfortunately, our common metaphos for computer interaction lead us away from the invisible tool, and towards making the tool the center of attention.

Work life and unexamined technological skills

Anthropological studies of work life [Suchman 1985, Lave 1991] teach us that people primarily work in a world of shared situations and unexamined technological skills.

Humanities exposing the invisible

To understand invisibility the humanities and social sciences are especially valuable, because they specialize in exposing the otherwise invisible.

The childhood metaphor

Our computer should be like our childhood – an invisible foundation that is quickly forgotten but always with us, and effortlessly used throughout our lives.

Intelligent Agents

A computer that I must talk to, give commands to, or have a relationship with, is a computer that is too much the center of attention. [...] Ubiquitous computing is exploring quite different ground from Personal Digital Assistants, or the idea that computers should be autonomous agents that take on our goals. The difference can be characterized as follows. Suppose you want to lift a heavy object. You can call in your strong assistant to lift it for you, or you can be yourself made effortlessly, unconsciously, stronger and just lift it. There are times when both are good. Much of the past and current effort for better computers has been aimed at the former; ubiquitous computing aims at the latter.

Virtual Reality

VR is extremely useful in scientific visualization and entertainment, and will be very significant for those niches. But as a tool for productively changing everyone’s relationship to computation, it has two crucial flaws: first, at the present time (1992), and probably for decades, it cannot produce a simulation of significant verisimilitude at reasonable cost (today, at any cost). This means that users will not be fooled and the computer will not be out of the way. Second, and most importantly, it has the goal of fooling the user — of leaving the everyday physical world behind. This is at odds with the goal of better integrating the computer into human activities, since humans are of and in the everyday world.

3 sizes of physical affordances

The physical affordances in the world come in all sizes and shapes; for practical reasons our ubiquitous computing work begins with just three different sizes of devices: enough to give some scope, not enough to deter progress. The first size is the wall-sized interactive surface, analogous to the office whiteboard or the home magnet-covered refrigerator or bulletin board. The second size is the notepad, envisioned not as a personal computer but as analogous to scrap paper to be grabbed and used easily, with many in use by a person at once. The cluttered office desk or messy front hall table are real-life examples. Finally, the third size is the tiny computer, analogous to tiny individual notes or PostIts, and also like the tiny little displays of words found on book spines, lightswitches, and hallways.


Most wireless work uses a figure of merit of bits/sec x range, and seeks to increase this product. We believe that a better figure of merit is bits/sec/meter3. This figure of merit causes the optimization of total bandwidth throughout a three-dimensional space, leading to design points of very tiny cellular systems.

Hidden terminal problem

A “media access” protocol provides access to a physical medium. Common media access methods in wired domains are collision detection and token-passing. These do not work unchanged in a wireless domain because not every device is assured of being able to hear every other device (this is called the “hidden terminal” problem).

Galileo's Availability in Urban Areas

Posted: December 31st, 2005 | No Comments »

With the first of the thirty Galileo satellite launched, it is still unclear to me on own much improvement in availability it will have over GPS. Apparently even with better behavior, Galileo will not solve all the problems in dense urban areas. In 2004, the European Union and the United States clinched a deal last year on making Galileo compatible with the GPS that should provide a full super-constellation to improve availability and accuracy in city centers.

Galileo Performance: GPS Interoperability and Discriminators for Urban and Indoor Environments concludes with:

Analysis of the potential for Galileo to serve mass-market users in high mask angle environments indicates that Galileo has a slightly better availability over Europe than GPS, but neither system alone provides reliable visibility of satellites.

and advocatates for GPS and Galileo interoperability:

System performance predictions suggest that an interoperable GPS/Galileo can offer significantly improved accuracy and availability over GPS alone, particularly in urban areas.

Effects of Pervasive Computing on Sustainable Development

Posted: December 31st, 2005 | No Comments »

Effects of Pervasive Computing on Sustainable Development provides an overview of a study commissioned by the Swiss Centre for Technology Assessment (TA-SWISS) to discuss the opportunities and risks of pervasive computing for sustainable development focusing on its impacts on human health and the environment. It explains that pervasive computing could amplify already existing problems related to the environment, human health, and society. Power consumption for digital networks, e-waste streams, and exposure to non-ionizing radiation may all increase.

Environmental Impacts
The study splits the environmental issues in: resource consumption, end-of-life treatment, and indirect effects:

Pervasive computing will bring about additional loads on as well as benefits to the environment. [...] The functional requirement of low energy consumption provides a great opportunity to the environment on the macro level as pervasive computing could increasingly replace the PC for many applications [...] However, due to the increasing number of components that will be used, the total material and energy consumption caused by the production of electronic goods [23] is still expected to accelerate global resource depletion. [...] Always-on devices in particular and devices in stand-by mode will also form a substantial part of the total electricity consumption. On the other hand, there is a great potential for power savings due to the trend to mobile devices because the acceptable weight of mobile devices limits battery size. [...] The increasing quantities and shorter service lives of components that accompany pervasive computing will most probably counterbalance or even outweigh the benefits obtained from progressing miniaturization. [...] Another environmental risk of pervasive computing is the release of pollutants caused by the disposal of the resulting waste.

Health-Related Aspects of Pervasive Computing
The usual concerns about pervasive computing are the unpredictable long-term physical affects of non-ionizing radiation (NIR). The most interesting to my research is the potential impact of poor usability, disturbance and distraction of pervasive computing on the user behavior:

Further health-relevant effects of pervasive computing can be caused indirectly by influences on user behavior and the social context encountered. [...] In particular, pervasive computing could cause stress for various reasons, such as poor usability, disturbance and distraction, the feeling of being under surveillance (privacy issues), the possible misuse of technology for criminal purposes, as well as increased demands on individuals’ productivity. [...] Although there is a promising opportunity for better adaptation of pervasive computing to human needs, experience with established ICT shows that interfaces with poor ergonomic quality are widely accepted by consumers. There is a general trend to frequent distraction of human attention caused by technical devices. Such disturbances are likely to increase in future due to the diffusion of pervasive computing gadgets. The question is still open as to how such harassments can be effectively prevented.

The last sentence hits the core of my current research interest

Via Nicolas: The dark side of Pervasive Computing: environmental issues

Resonances and Everyday Life: Ubiquitous Computing and the City

Posted: December 29th, 2005 | 1 Comment »

In Resonances and Everyday Life: Ubiquitous Computing and the City, Anne Galloway introduces ubicomp researchers with social and cultural studies (theories of everyday life). It is rather off my particular research interest but a macro-vision on ubicomp surely does not hurt. I found really interesting that we must understand what is invisible to us (engineers) in order to design for invisible ubiquitous computing.

“Mark Weiser wanted ubiquitous computing to become invisible, but he also called on the humanities and social sciences to make visible to engineers and computer scientists what is often invisible so that they could better design for context-awareness. Theories of everyday life are dedicated to that very task”

Anne mentions that

ubiquitous computing was positioned to bring computers to “our world” (domesticating them), rather than us having to adapt to the “computer world” (domesticating us)

and referring to Norman

“today, it is the individual who must conform to the needs of technology. It is time to make technology conform to the needs of people”.

In many ways, current ubicomp technologies are not fully ready yet (will they ever be?) for such a shift. Current ubiquitous environments won’t be accepted if we present them as fully adaptive and conforming to our needs. Because they simply cannot match these expectations. Constraints are not only technological, but also economical, physical and cultural. Instead of aiming for the undeliverable and when limits are reached, a pragmatic approach is to work on the human’s empathy for technology, that is having ubiquitous environment communicating their “state of servileness” and provide fail-over techniques to the user. Examples being: a positioning system unable to get a fix voluntary giving its user the hand for self-positioning, my mobile phone already warns that its battery will be discharged soon, or planning for sporadic connectivity.

User Needs for Location-Aware Mobile Services

Posted: December 29th, 2005 | 1 Comment »

Eija Kaasinen, User needs for location-aware mobile services, Personal and Ubiquitous Computing, Volume 7, Issue 1, May 2003, Pages 70 – 79 is a paper that studies location-aware mobile services from the user’s point of view. It draws high-level and non-ground breaking conclusions about key issues related to user needs, based on user interviews, laboratory and field evaluations with users, and experts evaluations of location-aware services. Even if the author acknowledges that context cannot be easily identified or measured, there is no mention to how users adapt their needs to these issues. This leads to the advocation for seamless services which is far from the current real-world constraints of context and location-aware systems. However there are interesting findings in terms of user perception of location-aware applications.

  • Users want to remain in control. One of the scenarios created a feeling of haste; the servant becomes a master that starts to give commands to the user.
  • Location-aware information was expected to be especially useful in special situations, e.g. in unfamiliar environments, when looking for a specific service or in emergency situations (spontaneous and occasional use).
  • Most users thought that they would use location-aware services occasionally and mainly in unfamiliar environments or in emergency situations. These needs indicate that the services should be easily available when the spontaneous need for them arise.
  • Interviewees did not accept the rational and purpose-oriented attitude to life that they identified in the scenarios. The scenarios were seen as going too far beyond the real needs of people.
  • It is not wise to restrict the available information only to the current location and time: the users may also need to plan their next activities or to return to previous activities.
  • In practice, people may not be willing to spend their time on something from which they do not get immediate benefit.
  • Most users did not accept the idea of being contacted by strangers (cultural bias?)
  • Ideally the user should see all the necessary information for a given task in a single view.
  • Need to be able to use the mobile system both on and off line.
  • It did not occur to most users that they could be located when using location-aware services.

This article was first dug out by Nicolas (Paper about user’s expectations when using LBS).

User-perceived Quality of Service in Wireless Data Networks

Posted: December 28th, 2005 | No Comments »

Anthony J. Saliba, Michael A. Beresford, Milosh Ivanovich, Paul Fitzpatrick, User-perceived quality of service in wireless data networks, Personal and Ubiquitous Computing, Volume 9, Issue 6, Dec 2005, Pages 413 – 422 is a paper that brings the computer science and a rather quantitative perspective to my research. I would classify it in the Human-Network Interaction category, because the machine is rather irrelevant in their study that illustrates the advantages of defining and assessing user-perceived quality of service (QoS) when dimensioning critical network parameters for optimized network performance. The authors are from the Telstra Research Labs.

In the past the term of QoS was a way to dimension wireless networks to run in the most efficient way possible. That is assuming that optimization of performance at the lower network layers will translate directly into an improved user experience. Nowadays, there is a trend reversal, looking at the user perceptions of the network performance to decide where dimensioning can have the greatest impact. Effective network performance becomes less about network characterisitcs and efficiency and more about satisfactory of having the user experience drive the notion of QoS. However, QoS is very application and context-specific because various applications require different levels of network performance to satisfy users. The growth in the wireless data sector rests upon two critical dependencies: network capability and a positive overall user experience. Thus, by understanding the relationship between the user experience and perceived quality of the service and the associated network performance, conclusion can be drawn as the required network performance to provide the necessary service quality to users on an ongoing basis.

QoS is often defined in terms of network performance or network characteristics while aspected of the user experience also need to be captured and assessed accurately using tools and metrics. A user’s behavior is most accurately predicted by analysing their mental constructs, context of interaction, motivations and the tasks they perform while using the network services [Distributed Multimedia and QOS: A Survey].

Studies on network QoS usually identify four main factors:

  • Reliability: how important and useful it is to know in advance the level of network performance
  • Efficiency: a measure of how quickly the system responds to requests
  • Predictability: the degree to which the user experience followed the expectations of the users
  • Satisfaction: what degree the user was satisfied with each experience.

The authors propose a wireless QoS hierarchy fitting into the open systems interconnection (OSI) layers to obtain an in-depth understanding of each layer’s performance and the relationship between layers in the hierarchy.
Qos Hierarchy

Seamful and Seamless Design in Ubiquitous Computing

Posted: December 27th, 2005 | No Comments »

Seamful and Seamless Design in Ubiquitous Computing is a technical report by Matthew Chalmers and Ian MacColl for the Equator Project. It is yet another paper suggesting more ‘visibility’ and recalling Weiser’s notion of ‘seamful’ interaction, with ‘beautiful seams’, similar ideas as Seamful Design for Location-Based Mobile Games. However here the authors focus on uncertainty and even more interestingly on appropriation (positive design approaches).

The notion of “invisible computer” is often translated into requirements for seamless integration of computer system components. Mark Weiser suggested that making things seamless amounts to making everything the same, and he advocated seamful systems as the goal. Making everything the same is easy; leeting everything be itself, with other things, is hard. Therefor seamlessness could mean sacrificing the richness of each tool in order to obtain bland compatibility. Seamful design is a pragmatic approach that lets a ubicomp systm be itself, accepting all its physical and computational characteristics (weaknesses or strenghts). The phyisical characterisitcs of ubicomp systems are often apparent as uncertainty and inaccuracy.

The mention the impact of uncertainty in shared context and location awareness. Something I would like to investigate in the upcoming weeks:

Spatial uncertainty is problematic for several reasons. The aim of shared spatial awareness is mutual visibility, indicating to other visitors what particular visitor might be viewing. Uncertainty about the action position of a PDA visitor showed in the spatial awareness displays by apparent jumps of up to 2m. This sometimes made difficult for trial participants to establish shared context although visitors did resolve some this uncertainty through talk.

and even put forward other technical and non-technical sources of uncertainty

Beyond the inaccuracy of physical sensing and the ambiguity of references, ubiquitous systems must increasingly deal with complex and dynamic technical problems related to bandwidth, power, latency, disconnection, and so forth. Non-technical aspects are also affected by uncertainty, such as awareness of others’ locations and activity. These are often apparent through the patterns of social interaction more than interaction with devices and interfaces. Privacy, for example, can be seen as explicit control of the degree of certainty we permit others to have about us, e.g. by permitting others to know roughly, but not exactly, where we are.

The act of permitting other to know roughly but not exactly is studies in Social Disclosure Of Place: From Location Technology to Communication Practices and Location disclosure to social relations: why, when, & what people want to share.

Ubicomp as part of CSCW raises issues of appropriation. In their paper on the duality of space and place (Your Place or Mine? Learning from Long-Term Use of Audio-Video Communication), Harrison and Dourish argue that an expensive, complex system they had observed couldn’t be “owned” by its users, inhibiting adoption and enjoyment. We should talk a view which “emphasises emergent communicative practices, rather than looking for the transfer of face-to-face behaviours.”

Other studies of media spaces and of other collaborative technologies, consistently point out that
accommodation and appropriation is key to the adoption of new technologies: users design their
activity to accommodate the particular technologies we offer them

Extending the analysis of Harrison and Dourish, one approach to designing for appropriation is to aim for systems whose underlying mechanisms are “literally visible, effectively invisible” in that everyday interaction does not require attention to these mechanisms’ representations—but one can selectively focus on and reveal them when the task is to understand or even change the tool.

A next step in seamful design of ubiquitous environment is to find patterns and correlations that describe which aspects of system structure, sensing and categorization to reveal, and in what form. We may be able to find correlations, and offer recommendations, but explanations will be harder to find.

The ultimate design goal here is a good tool lets users focus on their task – event when that task involves changing the tool itself.

Contextual Design

Posted: December 24th, 2005 | No Comments »

Contextual Design provides a way to model observed work. A Contextual Design process models the communication flow, sequence of work, workplace culture, physical space, and documents any relevant work artifacts.

Contextual Design Steps include:

  • Contextual inquiry – field interviews and observations at work site
  • Work Modeling – captures the work of indidividuals and organizations
  • Consolidation brings data from individual customer interviews together so the team can see common pattern and structure without losing individual variation.
  • Work redesign – to improve work by using technology to help people do their work Storyboards: how people will work with the new system
  • User environment design — the ‘floor plan’ of the new system
  • Prototyping
  • Prioritization and object-oriented design

Massive Vehicle Tracking in Britain

Posted: December 24th, 2005 | 1 Comment »

As announced for some time now, Britain is to become the first country in the world where the movements of all vehicles on the roads are recorded. The car location will be made by a network of already existing CCTV cameras which are being converted to read plates automatically night and day to provide 24/7 coverage of all motorways and main roads, as well as towns, cities, ports and petrol-station forecourts. It is an excellent example of massive tracking system that relies on the network being aware of the device and not the other way around (the device not being location aware)

CCTV plays already a big part of Britain’s every day life, the difference is that, in future, the car’s index plates will be read and the system will store the details of 35 million number-plate “reads” per day. This surveillance network is part of so-called “public protection”. The claim is to cross-check each number plate against a stolen and suspect vehicles database and to do anti-terrorism. Like silly (costly and mainly useless) airport security procedures it seems that this system would bother more the regular people than the targeted persons, because of course the national data centre will mainly check whether each vehicle is lawfully licensed, insured and has a valid MoT test certificate, and why not calculate the speed of the vehicle. Senior police officers have described the surveillance network as possibly the biggest advance in the technology of crime detection and prevention since the introduction of DNA fingerprinting.

This makes me think of the IMOHO inappropriate parental behavior of wanting to track their kids on their way to school to “protect them”. Should a government act the same? It is really worth the step for a safer society?

Britain will be first country to monitor every car journey

The Underwhelming Effects of Location-Awareness on Collaboration in a Pervasive Game

Posted: December 23rd, 2005 | No Comments »

Our paper “The Underwhelming Effects of Location-Awareness on Collaboration in a Pervasive Game” (by Nicolas Nova, Fabien Girardin, Gaëlle Molinari and Pierre Dillenbourg) has been accepted for the International Conference on the Design of Cooperative Systems (May 9-12, 2006, Carry-le-Rouet, Provence, France).


In this paper we seek to empirically study the use of location-awareness of others in the context of mobile collaboration. We report on a field experiment carried out using a pervasive game we developed called CatchBob!. Using both quantitative and qualitative data, we show the underwhelming effects of automating location-awareness. Our results indeed shows that automating this process does not necessarily improve the task performance and that it can be detrimental to socio-cognitive processes involved in collaboration such as communication or the modeling of partners’ intents. The paper concludes with some potential impacts for location-based application practitioners.

Keywords: location-awareness, socio-cognitive processes, pervasive game, cscw, field experiment.

Congrats Nicolas! You’re on a roll!