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Ubiquitous Computing - Computing in Context
PhD Thesis

Albrecht Schmidt (

Computing Department
Lancaster University,

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Albrecht Schmidt, PhD Thesis, November 2002

Ubiquitous Computing - Computing in Context

a thesis on Context-Awareness, Context Aware Computing, and Ubiquitous Computing

In December 2006 I have started the User Interface Engineering Group in Bonn.

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Title: Ubiquitous Computing Computing in Context

Albrecht Schmidt, MSc
Computing Department,
Lancaster University,
England, U.K.

Submitted for the degree of Doctor of Philosophy, November, 2002


Computers have advanced beyond the desktop into many parts of everyday life. Ubiquitous Computing is inevitably computing in context: it takes place in situations in the real world. So far most research, especially in mobile computing, has focused on enabling transparent use of computers, independently of the environment. An orthogonal research effort is to exploit context. The research reported here is investigating: how context can be acquired, distributed, and used and how it changes human computer interaction in Ubiquitous Computing.

Possible sensing technologies, in particular low level physical sensors, and perception techniques are assessed and their value for providing context in Ubiquitous Computing systems is analysed. Abstractions on sensor level, cue level, and context level are introduced, resulting in a flexible context acquisition architecture.

A bottom-up approach for modelling context aware systems is introduced. This makes use of the fact that context or domain knowledge is more general on the level of artefacts, than on the system level. The creation of context aware systems, based on this approach, is then investigated using the method of prototyping. To generalise and communicate results, a pattern language for context aware systems is suggested.

As context acquisition systems are mostly specific to a certain task, building such systems involves designing and building hardware and software. The research presented here shows methods, architectures, and tools to make the development process more efficient. The Smart-Its platform, a rapid prototyping system for context-aware Ubiquitous Computing systems, is introduced and use experience is reported.

The observation that context naturally surrounds us, led to the development of a communication platform. This platform provides an effective means to distribute and receive information based on spatial and temporal relationships of components.

In this research the notion of implicit human computer interaction, and in particular the use of context information as implicit input, is introduced. The implications on the user interface and on the human computer interaction process are analysed, as context is fundamentally different from events in user interfaces.

Finally the research presents an overview on how Ubiquitous Computing systems can be evaluated. Different techniques are assessed, and the concept of probing users and developers with prototypes is presented.

Download the full thesis as PDF.




Albrecht Schmidt, MSc, Dipl. Inf.

Computing Department
Engineering Building, Room A13
Lancaster University
Lancaster, UK


Tel: +44 (0) 1524 593675
Fax: +44 (0) 1524 593608


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