in: European Telematics: Advancing the Information Society. Proceedingsd of TAP Annual Concertation Meeting, Barcelona, 4-7 February 1998.
European Usability Support Centres: Support for a More Usable Information Society Nigel Bevan National Physical Laboratory, Usability Services Teddington, Middx, TW11 0LW, UK http://www.npl.co.uk/inuse
[email protected]
Summary Success in the information society requires products and services which are closely matched to user needs. This is difficult to achieve with traditional development procedures and methods. The European Usability Support Centres set up by the INUSE and RESPECT projects can assist organisations in adopting the most cost effective approaches to user centred design. Introduction Delivering a successful information society requires more than the right technology, infrastructure and applications: it means providing tools and facilities which support peoplesÕ work and leisure activities. Speculative introduction of new technology which is looking for an application succeeds occasionally (Post-It Notes and the Walkman being familiar examples), but the occasional successes are dwarfed by the all too frequent failure of leisure and business products and support services which fail to meet user needs. The TAP Ten Commandments were an attempt to impose user orientation on European projects which have previously had a reputation for technology push. Though a step in the right direction, the effectiveness of this user orientation has been muted by entrenched attitudes and processes which fail to take sufficient account of user needs. A major step towards solving this problem is for organisations to adopt emerging methods for user centred development to ensure that the resulting products and services are usable and have quality in use. The TAP projects INUSE, RESPECT and MEGATAQ have joined together to form a network of 12 European Usability Support Centres (EUSCs) to provide European projects and industry with training and support in the use of these methods. Potential benefits of usability Most existing development processes focus exclusively on adherence to technical and process specifications. The objective of introducing user centred methods is to ensure that real products can be used by real people to achieve their tasks in the real world. This requires not only easyto-use interfaces, but also the appropriate functionality and support for real business activities and work flows.
Usability should be the major design objective for an interactive product: that the product can be used for its intended purpose. Increased usability will bring significant benefits to European industrial competitiveness: • Increased efficiency. A system incorporating good ergonomic design and tailored to the preferred way of working, will allow the user to operate effectively and efficiently rather than lose vital time struggling with a poorly designed user interface and badly thought-out functionality. • Improved productivity. A good interface to a well designed product will allow the user to concentrate on the task rather than the tool which, if designed inappropriately, can extend rather than reduce the time to do a task, as well as directly affecting other aspects of performance or quality. • Reduced errors. A significant proportion of so-called Òhuman errorÓ can be attributed to a product with a poorly designed interface to functionality which is not closely matched to the userÕs task needs. Avoiding inconsistencies, ambiguities or other interface design faults reduces user error. • Reduced training. A poorly designed user interface and dialogue can prove a barrier to an otherwise technically sound system. A well designed system designed with a focus on the end-user can reinforce learning, thus reducing training time and effort. • Improved acceptance. This is particularly important where usage is discretionary. Users would rather use and would be more likely to trust a well designed system which gives access to functionalities which make information easy to find and provides the information in a format which is easy to assimilate and use. Barriers to usability With all these potential benefits, why are many systems still not designed for greater usability? Introducing successful user-centred design into a large organisation requires technical and cultural change as well as strategic commitment: • cultural: all those involved in the development of a system or product must be aware of the issues and activities involved in user-centred design to effect the best design decisions at a micro- and macro- level. Others affected by the system or product, for example end-users, who previously have not been involved in its development, need to be made aware of their new role in design. They must also put into place mechanisms for achieving the technical and cultural change outlined above. • technical: development processes and procedures must include the usability methods and activities which are appropriate for the organisation and whose purpose and benefit can be clearly demonstrated to the developers. Techniques are required for the selection of appropriate methods for each project, and for the dissemination of lessons learned to other projects in the organisation. • strategic: the organisation and its management must set usability as a principal objective for systems development, but until recently there has been no way to accurately specify usability
requirements prior to design. There is often a contractual requirement to deliver a product which matches the specification, but if the specification is not precise about usability, there is little incentive to make this a priority in design. Product developers regard it as inevitable that different users will have different perceptions of the usability of the product. As usability is regarded as a subjective judgement outside the control of the developer, meeting the technical specification becomes the sole objective of design. INUSE and RESPECT solutions Cultural: Assessing usability maturity The INUSE project has developed methods [6] for assessing an organisationÕs position on a usability maturity scale (which is also being proposed as an extension to SPICE [11]). This provides an indication of the management commitment to implement user-centred design: 0: Ignorance Ð ÒWe donÕt have problems with usabilityÓ No consideration of users. 1: Uncertainty Ð ÒWe don't know why we have problems with usabilityÓ Human-Centred processes are not implemented, or fail to achieve their purpose 2: Awakening Ð ÒWhy do we always have problems with usability?Ó Human-Centred processes are implemented but are performed by inappropriate staff using sub-optimal methods 3: Enlightenment Ð ÒThrough management commitment and improvement of humancentred processes we are identifying and resolving our problemsÓ Human-Centred processes are implemented and produce results, but these results do not always give the expected benefits to the software development process 4: Wisdom Ð ÒUsability defect prevention is a routine part of our operationÓ Human-Centred processes are integrated into the software lifecycle and used to improve all work products 5: Institutionalised Usability Ð ÒWe know why we do not have problems with usabilityÓ The culture of the organisation is human-centred The experience of INUSE and RESPECT is that most TAP projects are at level 1, 2 or sometimes 3 on this scale. Technical: Supporting user centred design ISO DIS 13407 [9] explains how to achieve usability by incorporating user centred design activities throughout the life cycle of interactive computer-based systems. User centred design is a multi-disciplinary activity, which incorporates human factors and ergonomics knowledge and techniques with the objective of enhancing effectiveness and efficiency, improving human
working conditions, and counteracting the possible adverse effects of use on human health, safety and performance. There are four user centred design activities that need to take place at all stages during a project. These are to: • understand and specify the context of use • specify the user and organisational requirements • produce design solutions • evaluate designs against requirements. The iterative nature of these activities is illustrated in Figure 1. The process involves iterating until the objectives are satisfied. The sequence in which these are performed and the level of effort and detail that is appropriate depends on the design environment and the stage of the design process. INUSE has produced a Handbook of User Centred Design [5] which recommends appropriate methods for implementing user centred design in different environments.
1. Plan the human centred process Meets requirements 2. Specify the context of use 5. Evaluate designs against user requirements
3. Specify user and organisational requirements 4. Produce design solutions
Figure 1 - User centred design activities
Strategic: Setting usability objectives The MUSiC project demonstrated that it is possible to develop methods for specifying and testing usability based on the principles of the ISO 9241-11 [8], which defines the usability of a product as the Òeffectiveness, efficiency and satisfactionÓ with which a well specified group of users can carry out a known set of tasks in a given context of use. The MUSiC methods available to EUSC partners include: the Usability Context Analysis Guide [4] which provides a procedure for documenting the context of use and context of evaluation; the Performance Measurement Method [14] which provides a reliable and repeatable method for measuring effectiveness and efficiency and diagnosing usability problems, and SUMI [12] and MUMMS [13] which enable different aspects of user satisfaction to be measured and areas of difficulty to be pin-pointed.
European Usability Support Centres INUSE, in conjunction with RESPECT and MEGATAQ, has set up a network of Usability Support Centres for the European information engineering industry. A co-ordinated service incorporating common core methods is being provided by centres including NPL, HUSAT (Loughborough), Lloyds Register (London), University College Cork, Fraunhofer IAO (Stuttgart), SINTEF (Oslo), Nomos Management (Stockholm), and other usability consultancies in Europe (see Figure 2). The centres are in a good position to assist Europe industry in achieving a usable information society.
SINTEF
Nomos
Multimedia Comm Group
HFRG
HUSAT NPL
WIT Lab
Lloyd's Register Fraunhofer-IAO CB&J CURE
Sistemas Expertos
SIEM
Figure 2. European Usability Support Centres
International Standards The RESPECT project has contributed to extending the principles of ISO 9241-11 into international standards for software quality, thus providing support for incorporating usability in systems design. ISO DIS 14598-1 [10] and ISO CD 9126-1 [7] make quality in use (synonymous with the ISO 9241-11 definition of usability) the major quality goal in systems development. ISO DIS 9241-11 describes how quality in use can be specified and measured, and ISO DIS 13407 specifies the user-centred design process which is necessary to achieve the usability and quality in use goals [3]. The close involvement of the main INUSE/RESPECT partners in previous projects (MUSiC, and MAPI) which contributed to the development of these standards means that their contents are closely aligned with the methods employed by the EUSCs. This contributes to both the credibility of the methods and their technical integrity, and also enables the EUSCs to use the methods to achieve compliance with these standards, when their use is called for in a contract. Support for a more usable information society Success in the information society demands easy to use products and systems which more closely match real user needs. A recent study by the ESSI PET project [15] found that 60% of software defects arise from usability errors, while only 15% of are related to functionality. Adoption of user centred methods supported by the authority of international standards provides a potential solution to these problems, and the EUSCs can help organisations to overcome the cultural and technical barriers to the implementation of the methods.
Acknowledgements This paper incorporates material produced by Ian Curson at NPL, and other INUSE partners. References 1. Bevan N (1995a) Measuring usability as quality of use. Journal of Software Quality, 4, 115130. 2. Bevan N (1995b) Usability is quality of use. In: Anzai & Ogawa (eds) Proc. 6th International Conference on Human Computer Interaction, July 1995. Elsevier. 3. Bevan N and Azuma M (1997) Quality in use: Incorporating human factors into the software engineering lifecycle. In: Proceedings of the Third IEEE International Software Engineering Standards Symposium and Forum (ISESSÕ97), p169-179. 4. Bevan N and Macleod M (1994) Usability measurement in context. Behaviour and Information Technology, 13, 132-145. 5. Daly-Jones, O, Thomas, C, Bevan, N. (1997) Handbook of user centred design. National Physical Laboratory, Teddington, Middx, UK. 6. Earthy, J (1997) Usability Maturity Model: Attitude Scale INUSE Deliverable D5.1.4 (s). http://www.npl.co.uk/inuse 7. ISO/IEC FCD 9126-1 (1998) Software quality characteristics and metrics - Part 1: Quality characteristics and sub-characteristics. 8. ISO DIS 9241-11 (1996) Ergonomic requirements for office work with visual display terminals (VDT)s - Part 11 Guidance on usability. 9. ISO DIS 13407 (1997) User centred design process for interactive systems. 10.ISO/IEC 14598-1 (1998) Information Technology - Evaluation of Software Products - Part 1 General guide. 11.ISO/IEC PDTR 15504 (1997) Software process assessment 12.Kirakowski J (1996) The Use of Questionnaire Methods for Usability Assessment. http://www.ucc.ie/hfrg/questionnaires/sumi/sumipapp.htm 13.Kirakowski J (1997) Measuring the Usability of Multi-Media Systems http://www.ucc.ie/hfrg/questionnaires/mumms/info.html 14.Macleod M, Bowden R, Bevan N and Curson I. (1997) The MUSiC Performance Measurement Method. Behaviour and Information Technology, 16. 15.Vintner, O. & Poulsen, P.M. (1996). Experience driven software process improvement, Paper presentation at Software Process Improvement ‘96, 3rd-5th December, 1996, Brighton.
