harnessing the power of formalism for understanding interaction
a tutorial at AVI 2004 <@avi2004> Gallipoli, Italy, May 2004

Alan Dix <@alan>
Lancaster University, UK


Tutorial notes now available! ... Download notes (PDF, 6.9Mb)

why come?

User interfaces and visualization are strange things ­ we are trying to squeeze the rich complexity of human interaction through the Cartesian mesh of a bitmap screen. By their nature computer systems are formal systems. By understanding this we can deliberately use the expressive power of formalism to understand some of this rich interaction.

This tutorial is intended for those wanting to begin using in formal methods in user interface modelling or to broaden their knowledge of the topic. It will be of value to those at AVI wishing to use formalism to give a more precise understanding of the interfaces they design, or for those who wish to integrate complex underlying algorithms and data structures with effective user interfaces.


It will review the use of formalism within interactive systems design and demonstrate some of the ways in which more formal approaches can give insight into new areas.

Indicative content includes:

  •  why formalism ­ what it is and why it is useful in general
  •  a brief history of formalism ­ from Aristotle to Alan Turing, two and a half thousand years of development
  •  types of formalism in interactive systems design: cognitive models, dialogue models, system models
  •  modelling interaction - introduction to techniques, notations, and common problems
  •  a practical success story ­ formalism really works … and why.


Alan Dix is Professor of Computing at Lancaster University. He has published widely in HCI (over 200 publications) and is the author and editor of several books including his monograph on "Formal Methods for Interactive Systems" and the co-authored "Human­Computer Interaction", which has become one of the principal textbooks in the field. In addition to his personal research record, his professional experience includes an initial training in mathematics, the design of agricultural crop sprayers, being associate dean for research at Staffordshire University, UK, and various consultancies, which, purely by coincidence, follow the wet theme and seem mostly to have been about the design of submarines and boats. He has also been a founder director of two Internet startup companies focused on intelligent agent technology and web community building. Alan's work is typically eclectic and often takes unusual viewpoints to tackle familiar and practical problems. Although his first love is mathematics, he has, at times, been accused of being a sociologist, got his fingers dirty in marketing and, when no one is looking, will play with toy cars and plastic spaceships.

sources and links

The tutorial will draw heavily on a book chapter:
A. Dix (2003). Upside down As and algorithms - computational formalisms and theory In HCI Models, Theories, and Frameworks: Toward an Multidisciplinary Science. John Carroll (ed.) Morgan Kaufman, 2003. pp. 381-429
And also on several chapters from:
A. Dix, J. Finlay, G. Abowd and R. Beale (2004). Human-Computer Interaction, third edition. Prentice Hall