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Usability evaluation techniques for digital library development
Working initially with the developers of the British Telecom Digital Library we identified usability issues facing both the users and the developers. The developers expressed hopes that recent changes to the interface had improved awareness of the content and features of the resource. The library has a common search interface which acts as a portal to a number of databases including technical abstract and index services. A study of the users found they reported difficulties finding information at the start of new projects. The librarians acting as expert intermediaries were able to track down hard to find information by fully exploiting the features available and their knowledge of the domain, resources and the interface. Reviewing information seeking models suggested that the activity of information seeking is a particular challenge to which the librarians were able to apply information retrieval skills not available to the casual user. Non scenario based usability methods such as heuristics were not able to identify problems resulting from a lack of key search skills. Claims analysis as a scenario based method offered the opportunity to describe the user and the activity in detail. Claims about usability of the design are derived from the scenario and supported by psychological research to validate the claims. Initial trials of the method found it was difficult to develop scenarios and identify claims. Information seeking models offered a source for describing different search activities including the browsing and iterative strategies used by the experts. A tutorial has been developed and presented at JCDL 2003 outlining the usability problems faced by users of digital libraries. The tutorial introduces information seeking models and cognitive models to support the development of different personas and different scenarios. These are used to generate claims about the effect of the design on the user (persona). Claims are analyzed for both positive and negative effects giving the developer the opportunity to reflect on design decisions and trade-offs that support improvement. These techniques will be further validated at BT, and with our collaborators at New Zealand and California Digital Libraries.
This is a three year
EPSRC funded project ending December 2003. For more details and publications
follow title link to project page.
User Centred Design
User centred design has been a key element in my work in new product development for some time, both with students and commercial development of new technology..
The basis of user centred design is an understanding of the context of use - identifying the users and the activities they are engaged in. In a major project users may include not just those with their hands on the product but supervisors, management, installation and maintenance staff and customers. They may well have different priorities that may affect requirements, and design decisions.
Similarly the tasks that the user undertakes need to be set in their wider context - using a mobile phone in daylight is fine - but what if you're making that critical emergency call in the dark and in a panic. In using a public information system the primary goal is to solve a problem eg find your way around a museum - only a limited number of specialised users such as the museum reception staff might ever want to be experts on the whole system.
Design is a complex process but the usability standard "Human Centred Design for Interactive Systems" (ISO 13407) provides a framework. The standard describes four principles of human-centred design *(www.system-concepts.com):
1. Active involvement
of users (or those who speak for them)
2. Appropriate allocation of
function (making sure human skill is used properly)
3. Iteration of design
solutions (therefore allow time in project planning)
4. Multi-disciplinary design
(but beware over large design teams)
The standard also describes four key human-centred design activities:
1. Understand and
specify the context of use (make it explicit: avoid assuming it is
obvious)
2. Specify user and organisational requirements (note there will be a
variety of different viewpoints and individuality)
3. Produce design solutions
(note plural, multiple designs encourage creativity)
4. Evaluate designs against
requirements (involves real user testing not just convincing
demonstrations)
Iterative design demands that the design is visualised at various stages, evaluated for usability and revised - at frequent intervals. This is especially important in the early stages of design where changes can be made quickly and economically rather than at the end where the cost of change may be prohibitive. Some innovation may be needed to help users understand and share your vision of the system such as role playing with different categories of users and task scenarios, story writing (or drawing), screen representations - pencil and paper, cardboard or PowerPoint.
Usability is defined as having three main components:
Effectiveness - does it 'do the job' - I always find it curious that a manufacturer should bother to make a toaster that burns half the slice of bread and leaves the other half untouched
Efficiency - is it quick and easy to use, easy to learn, does it help protect you from or even anticipate possible errors
Acceptance - do you like it, would you recommend it to your friends, is it a pleasure to use
For more information
on user centred design see:
*Tom Stewart http://www.system-concepts.com/
The Usability
Support Centre at Loughborough: www.lboro.ac.uk/eusc/index.html
Jakob Nielsen http://www.useit.com/
The Grey Revolution
"By the year 2020,
close to 50% of Europe's adult population will be aged 50 or over". (Helen
Hamlyn research centre http://www.hhrc.rca.ac.uk/)
There is an explosive growth in the number of over 50's who definitely don't see themselves as old, but who may have different needs and ambitions than the youth market (20-30 year olds), and the frail old (possibly over 80, but associated with failing health). Commercially they represent an important growth market who have considerable spending power, free of the constraints of dependent families and bolstered by successful pension plans.
I represented
University of East London on the EU funded GENIE (Gerontechnology education
network in Europe) project. While at UEL I wrote a research proposal to
investigate the ambitions and needs of the new grey market and how this
information could be used to inform the design process. The older people that I
have met through the University of the Third Age have an amazing zest for life,
and a wealth of experience that is quite unlike the stereotypes or the majority
of research which depressingly stress all the negative aspects of ageing. I also
wrote two articles for The Ergonomist offering the term Greynomics for the study
of this phenomenon - ergonomics for seniors. I reported on the modest
growth of interest in this area that includes the work of GENIE to develop
resource material for student designers, the new for old and genius project
briefs for the RSA student design awards, a Gerontechnology conference, and some
of the work at STAKES in Finland. Recently from Middlesex we have been looking
at some of the issues of accessibility of information technology for older
people and people with visual impairment.
See:
GENIE website:
http://www.gerontechnology.info/genie/genie/home.html
Helen Hamlyn
Research Centre at Royal College of Art: http://www.hhrc.rca.ac.uk/
STAKES, Finland: www.stakes.fi/include
The Ergonomics
Society: http://www.ergonomics.org.uk/
History
Previously I worked
extensively as a Human Factors consultant on a number of telecommunication
projects for ITT (now Alcatel), ETSI, Nortel, Philips PMR (now Simoco) and Cable
and Wireless on product development, user interface design, usability and user
guidance.
I am a fellow of the
Ergonomics Society and have been editor of The Ergonomist, member of the
Publication Committee and member of Council.
Contact
Tel: 020 8411
5098
Email: s.keith@mdx.ac.uk
IDC - School of Computing
Science
Middlesex University
Trent Park
Bramley
Road
London
N14 4YZ