An investigation and evaluation into the 'usibility' of human-computer interfaces using a typical CAD system
This research program covers three topics relating to the humancomputer interface namely, voice recognition, tools and techniques for evaluation, and user and interface modelling. An investigation into the implementation of voice recognition technologies examines how voice recognisers may be evaluated in commercial software. A prototype system was developed with the collaboration of FEMVIEW Ltd. (marketing a CAD package). Proposals for future research using the prototype system suggests the need for field trials to assess its usefulness in a working environment and to gain insights to end-user attitudes. A new generation of voice system is proposed based around a phoneme-based pattern matching paradigm, natural language understanding facilities and intelligent knowledgebased systems capable of building on knowledge by inference and deduction. In order to assess the 'usability' of the FEMVIEW CAD software a subject-base formal evaluation was conducted which involved: - (1) the analysis of responses to a multi-user survey of end-user attitudes; (2) collecting behavioural performance measures from students learning to use the software. (3) cognitive and affective data obtained from laboratory experimentation using experienced users of the CAD package. A theoretical approach to evaluation leads to the hypothesis that human-computer interaction is affected by personality, influencing types of dialogue, preferred methods for providing help, etc. A user model based on personality traits, or habitual behaviour patterns (HBP) is presented. Proposals are given to use the HBP model in future self-adaptive interfaces. Results from experimentation to justify the model are inconclusive. Finally, a practical framework is provided for the evaluation of human-computer interfaces. It suggests that evaluation is an integral part of design and that the iterative use of evaluation techniques throughout the conceptualisation, design, implementation and postimplementation stages will ensure systems that satisfy the needs of the users and fulfil the goal of 'usability'. The major contributions made to the knowledge of this subject can be summarised as follows: (1) the practical problems of implementing voice recognition technologies in commercial software; (2) the development of a new personalised user model which accounts for individual's idiosyncrasies; (3) methods for applying simple evaluation techniques in order to assess software 'usability'; (4) a practical framework for developing usable software.