AMO - the interface as medium

extended abstract

Alan Dix and Janet Finlay
At time of publication: HCI Group and Dept. of Computer Science,
University of York
Currently: Alan Dix
Lancaster University
Janet Finlay
School of Computing and Mathematics, Huddersfield University

Full reference:

A. J. Dix and J. E. Finlay (1989). AMO - the interface as medium. Poster sessions, HCI International'89, . Boston, 22.

See also:
longer version of this paper (unpublished)
the ecology of information web pages

We are interested in producing formal and conceptual tools for interface designers. This paper describes a development in the latter category.

Various interface styles suggest paradigms for understanding interaction. Direct manipulation suggests the interface as a passive entity, tools for the user to control. Intelligent interfaces suggest instead an active interface, a colleague which (or even who) cooperates with the user on the task in hand. User interface management systems typically have a paradigm between the two where the interface is seen primarily as a translator, or mediator between the user and the application. Each of these paradigms seem useful in different contexts, but mixing them runs the risk of getting the worst, rather than the best, of all worlds.

Viewing the interface as a medium allows us to make sense of the interplay between passive and active components of an interface. The word medium here is taken to include the whole software/hardware amalgam, with both its functional and aesthetic attributes. In particular it is not limited to the information theoretic concept of a channel or the physical characteristics of a device, although these will both be facets of the media. In this paradigm, we can decompose systems into agents (human or machine), media and objects (AMO).

The motivating example for this approach is of course mail and conferencing systems. Clearly when viewed as theoretical communication channels most such systems are identical: they differ more in the qualitative aspects of the interface. The important thing to note is that these non-functional differences such as pace and ease of interaction can make profound differences to the content of communication. This is typified by the differences between face-to-face, telephone and paper mail communication.

In the mail example, the total system consists of the medium and the people who are communicating. The medium is (relatively) passive and the people active. In general systems have other active members than just the humans and we refer to both types of active member as agents. The final classification, objects refers to those components which are passive, but are not merely artifacts of the interface, for instance data-files.

The distinctions introduced can be used purely descriptively or normatively in judging existing or putative systems. Examples of interface issues which can be addressed are:

In these and similar ways, we can use the proposed framework to analyse real world phenomena and their relationships to such interface techniques, and thus suggest directions for future development.

Alan Dix 5/7/98