The story about PalCom

The objective of the PalCom project is to develop an open architecture for palpable systems by the means of collaborative design processes.

The PalCom project develops software architecture and prototypes, where the latter to a large extent focus on healthcare, emergency services and landscape architecture.

Beyond predominant trends

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Ambient, pervasive and ubiquitous computing is quickly becoming a predominant trend within the IT industry and associated research work. They serve both as

  • a characteristic of ongoing developments within this area and
  • a powerful vision for longer term changes in our use of computing resources.

The PalCom project shares both these views.

On the one hand, the current development of new, small, specialized devices definitely points towards ambient computing being well on its way.

On the other hand, we share the vision that, in the longer term, ambient computing may provide new opportunities for qualitative improvements to our lives and the systems we use. 

Users in control

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In order to further the realization of this vision, however, it is not enough that devices become smaller, more powerful, less power consuming and less visible by being integrated into other artefacts.

It is of paramount importance that users of these new devices and systems understand them and their inter-relationships.

It is further important that they are able to maintain control of such devices and their interaction with different systems.

Finally they should have the possibility to deal with unforeseen situations and errors in adequate ways.
This is the overall objective of PalCom, namely to design a software architecture for this environment – an environment we have termed palpable computing.

The need for palpable computing

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Thanks to the bandwidth of wireless communications and in the miniaturisation of computing power, we can envisage 'exploding' computing capacity out of conventional systems and interfaces and embedding it in very small (or very large) communicating devices.

We might use a single device - a mobile phone, for example

  • to control surveying equipment on a tripod
  • to exchange data with colleagues
  • to turn the lighting or heating up and down
  • or to book our flight home.

We might also use the mobile phone to receive the medical records of a patient and display them on the TV set at her bedside at home. Assemblies of such devices might offer powerful services that are more than the sum of their parts.

This is the dream of ambient computing. But there is a corresponding nightmare.

Suppose that ambient computing catches on and really does become ubiquitous. If I enter a railway station, for example, literally thousands of ambient-capable devices and services might announce themselves to me, and these could even include those used by managers, signallers and drivers to control the movement of trains.

If I have to select explicitly whether and how to interact with each of these offered connections, I will quickly throw my ambient device in the bin.

If, on the other hand, the ambient system assumes that it can decide which interactions I want, it will very often be wrong, and the result will be at best irritating and at worst disastrous.

Palpable complements ambient

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We mean palpable systems must:

  • 'act appropriately', sometimes acting autonomously and sometimes deferring to the user.
  • provide the means for us to know that and how it has acted appropriately; otherwise we will not trust it. When deferring to the user, the system must provide means that allow the user to control it and its components
  • be capable of being noticed and understood

The PalCom challenges

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To address palpability, we capture six dimensions of the vision of ambient and ubiquitous computing, and challenge them by considering their opposites.
Users will often need to find a position that lies between the extremes:

  • invisibility - visibility
    When a supposedly seamless and transparent set of connections breaks down, for example, users should be able to make them visible and inspect what has gone wrong. 
  • scalability - understandability
    While ambient environments should be able to scale up to large numbers of participating elements, they should also remain understandable.
  • construction - de-construction
    Users should be able to deconstruct an ambient assembly of devices and services, both to inspect it for repair and to use its elements for new assemblies.
  • heterogeneity - coherence
    Coherence must be forged from heterogeneous materials, such as disparate digital and physical devices and information, while recognizing and where necessary preserving the particularities of each.
  • change - stability
    Changes – for example, of location, resources, context and activity – are normal in an ambient environment, but sometimes users need to be aware of the change and sometimes they need to experience highly stable adaptivity.
  • automation - user control and deference
    Users do not want to be constantly pestered with choices and they need to be able to delegate ‘routine’ decisions, but it is inevitable that the system will often guess wrong, so users must always be able to retrieve control – and must have the information to help them to know when they might want to do so.

Palpable applications must be able to make and support the making of optimal choices concerning each of these challenges.

A palpable architecture must support the construction and operation of applications that can do so.

That is why palpable computing is not just a specialised variant of ambient computing, but a necessary pre-requisite for any usable ambient system.

If more information on our work with the PalCom challenges please see

External deliverables

Software architecture

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New software architectures are needed to support palpability.

The principal aim of the project is to create an open architecture for palpable computing. The open architecture will consist of a set of specifications as well as a reference implementation of these specifications.

Flexibility and efficiency are keywords for palpable distributed system architecture, and visibility and construction are essential.

Read more about the PalCom Open Software Architecture

Application areas

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PalCom’s researchers find inspiration for palpable technologies in a number of application areas. Such areas have been carefully selected and provide the researchers with a wide array of settings where palpability is a concern.

All application areas are characterized by the use of a growing number of digital devices and a need for technologies that work better together and are easier to comprehend.

Last Modified: 15 March 2007, © PalCom