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User X – 'Design for Each'

By Scott Milne, published 15th November 2005.

The Original Position

In 1971 the political philosopher John Rawls published A Theory of Justice [1], where he described the 'original position' - a thought experiment he used to determine the nature of a fair society.

The original position works as follows: a jury of rational agents - each acting on behalf of a real citizen - must design a society that those citizens will then inhabit. Each agent must act in the best interests of the citizen they represent. Crucially, the agents must conduct this procedure behind a 'veil of ignorance', whereby they are prevented from knowing any morally irrelevant characteristics of that citizen, such as age, gender, religion, etc.

This veil of ignorance is what makes Rawls' thought experiment so appealing. Without it, each agent – acting in the best interests of their citizen – would compete to design a society which favoured individuals with certain characteristics. Without this prior knowledge though, the agents (being rational) would design a fairer society where each citizen would be assured a certain minimum standard of life, regardless.

Interface Design and the Veil of Ignorance

The situation faced by Rawls' jury of rational agents is similar to that faced by many of today's interface designers. With target audiences on a global scale, designers may find themselves incapable of making any reliable assumptions regarding users' characteristics. Instead, our naivety with regards to users' needs, combined with legal, social and economic imperatives, compels us to design for the widest possible audience.

But rather than follow an abstract principle of 'Design for All', could we instead design our interfaces in the spirit of Rawls' original position thought experiment: as though for a single user whose characteristics remain a mystery to us? How should we design the interface to ensure that User X would enjoy a sufficient degree of usability, regardless of their characteristics? What design methodologies are available to us?

Universal Design

Universal Design is a popular approach for designing interfaces to be accessible and usable to the widest possible audience. Universal Design has been described as: "The design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design" [2]

At first glance it certainly seems like an appropriate methodology – we don't know anything about User X, so let's aim to make the interface 'universally usable'.

It has been argued though [3, 4] that this focus on 'universal usability' can render an interface inappropriate for most actual individuals, and that the nature and range of user characteristics is such that the needs of one group are likely to conflict with the needs of another. So, inherent in the Universal Design approach is the danger of 'lowest common denominator' design which limits the effectiveness of the interface for most actual end users. It may even encourage design which, through its uncompromising attempt at universality, actually reduces usability for many user groups.

More From Rawls

Rawls was sure that his jury of rational agents would follow the 'maximin' principle, the 'maximum minimum', a principle borrowed from Game Theory which, in terms of social justice, seeks to ensure the highest possible payoff for the least well off. Isn't this what Universal Design also attempts to achieve? Perhaps, but Rawls was careful to point out that the maximum minimum is unlikely to be achieved simply by forcing 'equality' onto the citizens in a kind of communist fashion.

A society is quite a different thing from an interface of course, and it would be counterproductive to force the analogy too far. For example, Rawls goes on to discuss his 'principle of difference'. He insisted that the jury of rational agents would allow for a degree of difference in living standards, so that there would be sufficient incentives for individuals to improve their lot. This would then strengthen the overall economy of the society and in turn increase the standard of life for even the least well off. Thus, by allowing for a degree of difference, the maximum minimum is actually increased.

It is difficult to imagine how Rawls' 'principle of difference', 'incentives' and his notion of 'least well off' could fit usefully (or even meaningfully) into a methodology for interface design. However, the original position thought experiment has added an interesting element to our search for an appropriate interface design methodology: the unknown individual, User X.

This focus on a real user – one whose characteristics remain a mystery to us – keeps us grounded in the reality of designing for actual people, rather than statistical averages.

Beyond Universal Design

As mentioned before, so many of today's interface designers are faced with a 'veil of ignorance' regarding the characteristics of their users. Any heterogeneous group of users will contain a variety of characteristics which affect their interaction with an interface, including age, gender, computer literacy, domain expertise, physical/cognitive disabilities, and so on. However, to deal with this reality by considering such differences to be a constraint on design is what makes Universal Design an inappropriate methodology for the digital space.

Universal Design may have been suited to the design of the built environment, but the flexibility afforded by the digital environment means that interfaces can easily adapt to suit the diverse needs and preferences of different individuals. Of course, ensuring a basic minimum level of accessibility is important and necessary. But rather than this being the sole focus of our methodology, it ought to be the framework within which the real focus, the individual user, is placed at the heart of it all – user-centred design.

User Centred Design

User-centred design is qualitatively different from the 'lowest common denominator' approach. It encourages and requires the designer to move beyond the notion of the statistically average user, towards an appreciation for the coexistent yet often incompatible needs of different individuals. This reality is one which the Universal Design methodology is ill-equipped to deal with.

A range of user-centred design methodologies and techniques exist which can raise designers' awareness of the needs of real users. The most obvious of these and arguably the most effective, is to include real users in the design process. There a few experiences more excruciating for a designer than seeing people struggle to use their interface effectively. The immediacy of this experience and the first-hand knowledge it provides is rarely forgotten. Since we do not know the characteristics of our mysterious User X, we will want to involve a broad and representative set of users in this process, giving ourselves the best possible chance of evaluating the interface from something close to User X's perspective.

While involving real users is probably the most effective approach, it may not be realistic to expect designers to do this at every stage of the design process, given financial and time constraints. A good supplementary strategy is the use of Personas, effectively imaginary friends like our User X. However, unlike User X – whose anonymity is vital – we give characteristics and traits to each persona, in order to build a clear picture of a potential user of our interface. The value of personas is that, however imaginary, their inclusion in the design process reminds us once again that we are designing an interface for real individuals, not statistical averages.

Design for Each

The user-centred design methodology retains an essential framework of universal access, but rather than following the 'lowest common denominator' approach to serve the statistically average user, it requires us to focus on individuals and accommodate – even celebrate – human diversity.

The inclusion of User X turns the Universal Design model inside out – it refuses to design a digital environment by focussing on a non-existent average user. Instead it requires us to focus on individuals by asking: what if User X had the following set of characteristics? Or this set? Or that set? All the time though, we are reminded that User X, despite their anonymity, is a real human being whose best interests we wish to secure, by designing an interface that they can use as effectively as possible given whatever characteristics they may possess.

Perhaps an appropriate summary of this approach is 'Design for Each' – a reminder of the one characteristic that all end users do have in common – their individuality.

References

John Rawls, A Theory of Justice (Revised edition, Oxford University Press, 1999), ISBN 019825055X
"What is Universal Design?" The Centre for Universal Design, Copyright 1997 - http://www.design.ncsu.edu:8120/cud/univ_design/princ_overview.htm
"User Sensitive Inclusive Design", Alan Newell & Peter Gregor, JIM 2001 Interaction Homme/Machine & Assistance (4/5/6 July, France Invited Lecture 2001) pp.18-20
"User Sensitive Inclusive Design - In Search of a New Paradigm", Alan Newell & Peter Gregor, In: CUU 2000 First ACM Conference on Universal Usability (USA 2000) (ed. J. Scholtz and J. Thomas) pp.39-44