Hierarchical Task Analysis (HTA) is a core ergonomics approach with pedigree of over thirty years continuous use. At its heart, HTA is based upon a theory of performance and has only three governing principles. Originally developed as a means of determining training requirements, there was no way the initial pioneers of HTA could have foreseen the extent of its success. HTA has endured as a way...

This paper addresses the problem of the articulation between task modelling and system modelling in the design of interactive software. We aim at providing solutions allowing the software designers to use efficiently task models during the design process, and to check that the software being built actually corresponds to the requirements elicited during the task analysis phase. The proposed app...

This paper describes research carried out at Loughborough University in the UK into the areas of ‘design for all’ and accessible transport. The research addresses two common needs for designers and ergonomists working towards developing more inclusive products and environments, namely data on users that is accessible, valid, and applicable and a means of utilising the data to assess the accessi...

To build software which, at the press of a button, can tell you what cognition related hazards there are within an environment or a task, is probably well into the future if it is possible at all. However, incorporating existing tools such as task analysis tools, interface design guidelines and information about general cognitive limitations in humans, could allow for greater evaluative options...

Analyzing a task into Goals, Operators, Methods, and Selection rules (GOMS) is an established method for characterizing a user's procedural knowledge. When combined with additional theoretical mechanisms, the resulting GOMS model provides a way to quantitatively predict human learning and performance for an interface design, in addition to serving as a useful qualitative description of how the ...

Real work is complex and rich, involving other people, physical artefacts and constant re-planning of tasks to accommodate the contingencies of the situation. This rich ecology of work is often seen as opposed to more structured and formal methods of task analysis and interface design. This paper discusses a range of phenomena related to ecological settings and show how they can be incorporated...

Purpose – Modelling users’ interactions online is envisaged to allow developers to increase the usability of online systems and will aid system developers in building better systems to meet users’ needs, hereby creating better system design processes. Design/methodology/approach – The normative task model that was developed in this paper was created through an expert review of 14 online grocery...

This thesis presents a new interaction metaphor for object-centric tasks in the form of a prototype VR system, ALCOVE. Our new interaction metaphor is based on the observation that many users perform object-centric tasks: tasks centered around objects that must be manipulated and examined in detail. Although such tasks are numerous, traditional VR systems have yet to provide an interaction meta...

Up today, formal methods have mainly been used to allow designers to verify that software conforms to its specification. In this article, we propose a validation method and a tool to analyse whether the design actually fulfils the original requirements for the system. The principle of our validation method is to generate the complete set of possible user interaction sequences from the task anal...