Wednesday 15 August 2007

Ubiquitous, Pervasive and Ambient Computing – Clarification of Terms

In the resent month the question about ubiquitous, pervasive, ambient computing came up several times. An email by Jos Van Esbroeck motivated me to write my view on it…

Clarifying the terms seems an ongoing process as various communities and individuals use each of those terms for new things they are doing.

For me the best way to discriminate the terms ubiquitous computing, pervasive computing, and ambient intelligence is by their origin, history and research communities.

The first term (ubiquitous computing, ubicomp) is linked to Mark Weiser and his vision of computing in the 21st century [1]. In the research community its is very much connected to ubiquitous and pervasive systems that have the user somewhere in the loop. The ubicomp conference [2] seems more focused on user experience than on pure technology.

Pervasive Computing was pushed in the mid 1990s, more by industry and in particular by IBM. Pervasive computing seems from its origin more focused on technologies and solutions than on a particular vision. The two major conferences related to this topic: pervasive [3] and percom [4] are more systems and network focused, however always keeping some attention to the user experience perspective. Here, in particular with percom, many in the research community have their origin in the networking and distributed systems world. To me pervasive computing seems more technical than ubiquitous computing and includes systems that do no have direct human users involved.

The term ambient intelligence was introduced by the European funding agencies in the Framework 5 vision. Around the same time as the Philips Home-lab that drives the term, too. Here, similar to ubicomp, the vision of a new quality of user experience is a driving factor. The research that falls under this label by now is broad and I think it is very similar to the research in ubiquious computing. There is also a European conference on ambient intelligence [5].

Many people that are involved in ubicomp/pervasive/percom are also active in one more traditional research community. In particular many people are additionally involved in user interface research (e.g. CHI-Community), mobile computing and mobile systems, networking and distributed systems.

A very early topic related to the whole field is context-awareness as introduced by Schilit [6] who was working with Weiser. In my PhD dissertation I have looked more into the relationship between ubicomp and context-awareness - it has the title Ubiquitous Computing - Computing in Context [7]

In parallel subtopic in the above field have emerged that look at specific aspects, e.g. internet of things [8] (not necessarily a human in the loop), wearable computing (computing in cloth), smart environments (computing in buildings and furniture), tangible and embedded interaction [9] (looking at the interaction side), smart objects, ... and probably many more.

There is also an interesting trend that many of the topics, if they are a bit matured, move back into the traditional communities.

[1] Mark Weiser. The Computer for the Twenty-First Century. Scientific American 265, 3 (September 1991), 94-104
[6] B. Schilit, N. Adams, and R. Want. (1994). "Context-aware computing applications". IEEE Workshop on Mobile Computing Systems and Applications (WMCSA'94), Santa Cruz, CA, US: 89-101 .
[7] Albrecht Schmidt(2003). "Ubiquitous Computing - Computing in Context". PhD dissertation, Lancaster Univeristy.
[8] http://


Unknown said...

Nice overview, I posted a link to it on

Also, I always found it amusing to type "define: pervasive computing" into Google and follow the Wikipedia link (hint: read the title!).

Andrew Kun

Karl-Petter Åkesson said...

Hi Albert,

just read your article and it made me reflect upon some things.

The other day me and Staffan Björk started to discuss the distinction between Pervasive Gaming and Ubiquitous games which is interesting in relationship to the distinction you do between pervasive and ubiquitous computing. From mine and Staffans viewpoint being involved in the UbiComp research and more started to look at possibilities with this for games it was natural to start to call these games Ubiquitous computing games or shorter ubiquitous games. Though when we started collaborate with the industry preparing the project application for what became IPerG we realized the industry already had coined a term for these kind of games, pervasive games. So we started to use that term instead and through out the life of IPerG atleast for us involved in the project the term has more and more become a term for games in the physical surrounding not necessarily using technology at all :-) So in in the area of gaming the pervasive end is less involved with technology while the ubicomp are more.

The lunch discussion was about how Jane McGonical defines the terms in her dissertation where she introduces ubicomp games, in comparison to ubiquitous and pervasive games. Here distinction looks more at the purpose behind the game, being a research vehicle for UbiComp researchers or an entertainment artifact.

Some more terms related to these, though maybe not used that often, are the invisible computer as defined by Donald Norman in his book The Invisible Computer and the dissapearing computer which was coined by Jakub Wejchert when launching the EU research program called the same.