Alan Dix - research topics

Status-Event Analysis

A theme that has run through my work for several years has been the analysis and specification of interfaces including both status and event phenomena. The word 'event' is self-evident. Whereas events happen at a particular time, status refers to phenomena which have some continuity. That is anything which for a period of time can be sampled or observed. Examples of such phenomena are:

This distinction is simple but very powerful because properties concerning the distinction appear very robust. The same phenomena are observed in human-human human-computer and computer-computer interaction. For example, one of the ways an active agent can observe a change in status is to poll it. This happens in machines and also when a person looks at a watch.Unfortunately most specification languages deal with only status or events. This means that the crucial properties which arise in the interplay between them cannot be expressed. Furthermore, when phenomena of one type are described in terms of the other important implementation decisions are implicitly made. Work in this area has included extending event based notations to include status descriptions and also unpacking in a comprehensive manner the various ways that status and event phenomena are mediated by one another.

In his work on auditory interfaces Steve Brewster used Status-Event analysis, but added an extra category, mode. In some ways mode can be seen as a special case of status, but one that for the purposes of his work needed to be promoted to be 'first class' in the framework.

Andy Wood has used Status-Event analysis as one of theoretical foundations of cameo, an architecture for constructing potentially distributed agent-based applications. This was then used in the construction of CyberDesk a Java library and user interface for dynamic integration of desktop applications.

Status-event analysis is also one of the driving forces behind aQtiveSpace architecture, which powers aQtive's onCue Internet software. Find out more about the meeting of theory and commercial practice on aQtive's research pages.

See also


Some online papers


Other related publications

A. Dix, J. Finlay, G. Abowd and R. Beale (1993).
Section 9.4: Status/Event Analysis, Human-Computer Interaction.
Prentice Hall. second edition coming soon


Other people's papers related to Status-Event stuff


maintained by Alan Dix