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:

• Events:
  • clock: alarm rings
  • interface: beep or buzz
• Status:
  • clock: the hands on the clock face
  • interface: the contents of the screen

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

• my pages on web architectures, which uses status-event analysis to analyse notification servers; and issues of time in the user interface.
• the Bibliography of Event Papers by Adam Rifkin and Rohit Khare
• the TACIT project, an EU funded consortium that addressed issues of continuous interaction.

Some online papers

• A. Dix, J. Leite, and A. Friday (2007).
  XSED – XML-based Description of Status–Event Components and Systems. In Proceedings of Engineering Interactive Systems 2007, IFIP WG2.7/13.4 Conference, Salamanca, March 22­24, 2007, LNCS (to appear).
  abstract and XML listings
• A. Dix and G. Abowd (1996).
  Delays and Temporal Incoherence Due to Mediated Status-Status Mappings.
  (part of report on Workshop in Time and User Interface Design,. Glasgow, 1995).
  SIGCHI Bulletin, 28(2) pp. 47-49.
  full paper
• A. Dix and S. A. Brewster (1994).
  Causing Trouble with Buttons.
  Ancilliary Proceedings of HCI'94, Glasgow, Scotland. Ed. D. England.
  full paper (html) || full paper (Word 5.1 stuffed binhex)
• A. Dix (1993).
  An agent based architecture for groupware applications.
  unpublished report, Computer Science Department, University of York.
  full paper
• A. J. Dix (1991).
  Status and events: static and dynamic properties of interactive systems.
  Proceedings of the Eurographics Seminar: Formal Methods in Computer Graphics, Ed. D. A. Duce. Marina di Carrara, Italy.
  abstract || full paper (html)
• G. Abowd and A. Dix (1994).
  Integrating status and event phenomena in formal specifications of interactive systems.
  SIGSOFT'94, Ed. D. Wile. New Orleans, ACM Press. 44--52.
  abstract || full paper (compressed postscript, 112K) || full paper (PDF, 184K)
• A. Dix and G. Abowd (1996).
  Modelling status and event behaviour of interactive systems.
  Software Engineering Journal, 11(6) pp. 334-346.
  abstract || full paper (PDF, 122K)
• Alan Dix (1998).
  Finding Out - event discovery using status-event analysis
  Formal Aspects of Human Computer InteractionFAHCI98, Sheffield, 5th&6th September 1998.
  abstract || full paper (pdf) || full paper (compressed postscript)

• A. Dix, T. Rodden, N. Davies, J. Trevor, A. Friday, K. Palfreyman (1999).
  Exploiting space and location as a design framework for interactive mobile systems
  ACM Transactions on Computer-Human Interaction (TOCHI), in press.
  abstract || full paper (pdf)

Other related publications

• A. J. Dix (1991).
  Modelling and analysis of status input - when mice shouldn't drag their tails.
  In A Collection of Papers on HCI Ed. G. D. Abowd. YCS 156, University of York, Dept. of Computer Science.
• A. J. Dix (1991).
  Formal Methods for Interactive Systems.
  Academic Press.
  table of contents

Other people's papers related to Status-Event stuff

• Brewster, S.A., Wright, P.C. & Edwards, A.D.N. (1994).
  The design and evaluation of an auditory-enhanced scrollbar.
  Proceedings of CHI'94, Ed. B. Adelson, S. Dumais, & J. Olson. Boston, Massachusetts: ACM Press, Addison-Wesley, pp. 173-179.
  full paper in Microsoft Word 5.1 (32K) || compressed postscript (220K) || Adobe PDF (53K)
• Brewster, S.A. (1994).
  Providing a structured method for integrating non-speech audio into human-computer interfaces.
  PhD Thesis, University of York, UK.
  thesis abstract || introduction || full thesis in Microsoft Word 5.1 (552K) || compressed postscript (*4.6MB*)
• Wood, A., A. K. Dey and G. D. Abowd (1997).
  CyberDesk: Automated Integration of Desktop and Network Services,
  Proceedings of CHI'97, ACM Press, 552-553.
  full paper
  This paper and the follwing one use status-event anlysis to guide the design of an agent architecture,
• Wood, A.(1998)
  CAMEO: Supporting Agent-Application Interaction,
  PhD Thesis (University of Birmingham, UK, 1998).
• C.A. Wüthrich (1999)
  An Analysis and a Model of 3D Interaction Methods and Devices for Virtual Reality,
  Design Specification and Verification of Interactive Systems'99, eds. D. J. Duke and A. Puerta. SpringerWienNewYork. pp.18-29.
  This paper proposes a model based on systems theory, which allows status behaviour (although the event behaviour is less well integrated).
• M. Massink, S.Smith, D.Duke (1999).
  Towards Hybrid Interface Specifications for Virtual Environments,
  Proceedings of DSVIS'99, University of Minho, Braga, Portugal, June 1999.
  abstract
  This paper and the one below use HyNet, a form of PetriNet augmented with continuous behaviour specified by differential equations. This models both discrete and continuous phenomena, but, with many hybrid formalisms, HyNet assumes that continuous in time (status) phenomna are also continuous value phenomena.
  
• G.Doherty, M.Massink, G.Faconti, L.A.Watts (1999).
  Modelling Continuous Interaction for Design
  TACIT technical report TACIT-TR011