Richard M. Young

Four Easy Pieces for Assessing the Usability of Multimodal Interaction: The Care Properties

We propose the CARE properties as a simple way of characterisin g and assessing aspects of multimodal interaction: the Complementarity, Assignment, Redundancy, and Equivalence that may occur between the interaction techniques available in a multimodal user interface. We provide a formal definition of these properties and use the notion of compatibility to show how the system CARE properties interact with user CARE-like properties in the design of a system. The discussion is illustrated with MATIS, a Multimodal Air Travel Information System.

Separating User and Device Descriptions for Modelling Interactive Problem Solving

We are constructing models of interactive problem solving, accounting for the general problem solving techniques people exploit in performing tasks with computers, the device-specific knowledge they need, and the sources of that knowledge. We present an approach that allows us to specify separately the behaviour of the computer system, the problem solving capabilities of the user, and the knowledge the user applies when using the system. This allows us to recognise design features that depend on the user keeping track of non-displayed aspects of the device state, as well as those the user can see.

Multidisciplinary Modelling for User-Centred System Design: An Air-traffic Control Case Study

This paper reports work investigating how user and system modelling techniques can be integrated to support the design of advanced interactive systems, and how such modelling can be effectively communicated to design practitioners in order to evaluate their potential. We describe a large scale modelling exercise concerning a flight sequencing tool for air-traffic controllers. We outline the kinds of system and user analysis possible with the different modelling techniques, and the approach used to integrate and communicate the modelling analyses to the system’s designers. We then discuss the value of these techniques against several key criteria. The designers evaluated the modelling positively in many respects, including a commitment to explore further how user modelling can be integrated with their formal methods. We conclude that the scenario of HCI modellers working in collaboration with designers is feasible, and has analytic power.

HCI theory on trial

The third approach, proposed by John Long and his colleagues at the Ergonomics Unit, University College, London, proposes the development of prescriptive engineering design principles, both substantive and methodological, which in the long term would support practices seeking solutions to the general design problem of HCI. The principles would derive from an engineering conception of HCI, which in the short term supports the development of techniques and methods for effective design. The proponents will discuss how their approaches can support design practice and the ways in which theories are made available to the designer, either as artifact-products, predictive models, prescriptive guidelines and methods, or simply as designers’ “tools for thought”.