Designing a more Inclusive World

Professor John Clarkson, University of Cambridge

Good design is good business. Research by the UK Design Council (2005) has shown that an index of design aware companies outperformed the FTSA All share index by over 200% in both bull and bear markets over a 10 year period. There are clearly other indicators of good business management apart from design, however, the evidence that 'good design is good business' is compelling.

Design is not optional, it is an inevitable consequence of specifying or developing a product or service. The question is whether your design is good, bad or indifferent. Good design helps to manage development risk, asking:

  • Are you building the right products (or
  • Are you building the product right?

In addition, since the cost of change increases exponentially throughout the design and development lifecycle (Mynott et al., 1994), it is imperative that the project team have a thorough understanding of the real user and business needs at the start of the design process and correctly translate these needs into an appropriate requirements specification. This is particularly relevant for Universal Design, where the objective is to design products and environments that are usable by all people, to the greatest extent possible, without the need for adaptation or specialised design (Mace et al., 1991).

Many exemplars of Universal Design exist from such companies as ErgonomiDesign (www.Ergonomidesign.Com), IDEO (www.Ideo.Com), Smart Design (www.Smartdesignworldwide.Com), Factorydesign ( and Sprout Design ( to name just a few. To understand their success it is first important to understand the drivers behind Universal (or Inclusive) Design.

An Ageing World

The demographics of the developed world are changing; longer life expectancies and a reduced birth rate are resulting in an increased proportion of older people within the adult population. This is leading to a reduction in the Potential Support Ratio (PSR), which is the number of people aged 15-64 who could support one person aged over 65 (UN, 2004):

  • In 1950 the worldwide PSR was 12:1 ;
  • In 2000 the PSR was 9:1 ;
  • By 2050 it will be 4:1 globally and 2:1 in the developed

Maintaining quality of life and independent living for this ageing population is increasingly important and will soon be an absolute necessity for all countries in both the developed and developing world.

With increasing age comes a decline in capability (Figure 1[1]), yet often increased wealth and free time. Where previous generations accepted that capability loss and an inability to use products and services came hand in hand, the baby-boomer generation now approaching retirement are less likely to tolerate products that they cannot use, especially if due to unnecessary demands on their capabilities.

Graph1Figure 1 - Variation of capability within the Great Britain population (Grundy et al., 1999)

Typically, people are viewed as being either able-bodied or disabled, with products being designed for one category or the other. In fact capability varies continuously, and in reducing the capability demands of a product, inclusive design helps meet the needs of those who are excluded from product use, and improves the product experience for many others. This is consistent with research undertaken by Philips (2004) which found that two thirds of the population as a whole have difficulties with technological products (Figure 2[2]).

Graph 2Figure 2 - Philips (2004) many people have difficulties with technological products

When the capability demand of a product exceeds that of the user, they can no longer use it. Often this is seen as the person's fault for having a poor memory, reduced strength or imperfect vision. However, inclusive design places the responsibility with product designers to ensure that the capability levels required to use a product are as low as possible.

In the UK there are approximately 60 million people, where this single number hides significant diversity of age, status and capability:

  • Half of all adults are aged 47 or over;
  • The gender ratio is approximately 50 : 50;
  • 23% are grandparents and 18% are children;
  • 17% are disabled;
  • 14% have arthritis and 2.5% have diabetes.

As a consequence, it is normal to be different.

Inclusive Design

The British Standards Institute (2005) defines Inclusive Design as "The design of mainstream products and/or services that are accessible to, and usable by, as many people as reasonably possible... Without the need for special adaptation or specialised design."

In this sense products must be:

  • Functional - providing suitable features
    to satisfy the needs and desires of the intended users;
  • Usable - providing pleasure and
    satisfaction in use through easy operation;
  • Desirable - conferring social status, or
    providing a positive impact on quality of life, whilst being aesthetically
    striking or pleasant to touch;
  • Viable - assuring business success through
    delivery to market at the right time and at the right price.

Any potentially inclusive product or service is developed by starting from a challenge, captured as a perceived need. Transforming this need into a solution that can successfully satisfy the real need requires an appropriate design process. There are many ways to describe this transformation, but the 'waterfall' model (figure 3) is one of the most useful:

  • Discover - the systematic exploration of
    the perceived need to ensure the right design challenge is addressed, with due
    consideration of all stakeholders; leading to the first output, an
    understanding of the real need;
  • Translate - the conversion of this
    understanding into a categorised, complete and well defined description of the
    design intent; leading to the second output, a requirements
  • Create - the creation of preliminary
    concepts that are evaluated against the requirements; leading to the third
    output, concepts;
  • Develop - the detailed design of the final
    product or service, ready to be manufactured or implemented; leading to the
    final output, solutions.

Note that all decisions made throughout the process affect the level of design exclusion. In addition, knowledge of the intended users is particularly important.

Figure 3 - An inclusive design process (Clarkson et al., 2007)

Understanding Users

Any interaction with a product or service typically requires a cycle where the user perceives, thinks and acts; where for the most part, perceiving requires sensory capability, thinking requires cognitive capability, and acting requires motor capability (figure 4). The interaction between a product or service and the user's capabilities is also influenced by the environment in which it is used.

Figure 4 - The product interaction cycle

The following seven capability categories are helpful to measure a person's capability, or assess the ability level that a product demands in order to use it (Keates and Clarkson, 2003):

  • Vision is the ability to use the colour and brightness of light to detect objects, discriminate between different surfaces,or the detail on a surface;
  • Hearing is the ability to discriminate specific tones or speech from ambient noise and to tell where the sounds are coming from;
  • Thinking is the ability to process information,hold attention, store and retrieve memories and select appropriate responses and actions;
  • Communication is the ability to understand other people, and express oneself to others (this inevitably overlaps with vision,hearing, and thinking);
  • Locomotion is the ability to move around, bend down, climb steps, and shift the body between standing, sitting andkneeling;
  • Reach & stretch is the ability to put one or both arms out in front of the body, above the head, or behind theback;
  • Dexterity is the ability of one or both hands to perform fine finger manipulation, pick up and carry objects, or grasping and squeeze objects.

The interaction between a product and the user's capabilities is often complex and at the same time rather subtle, hence the involvement of the user in product and service design is critical to the success of the final outcome. They may be employed in a number of ways to maximise their influence on the understanding of the real need, in defining requirements, and in evaluating concepts and final solutions. Users may include:

  • Average users - who are generally
    able-bodied can advice on the usability and desirability of the emerging product
    or service;
  • Extreme users - who, by describing the
    impact of their sever capability loss, can often inspire creative
  • Boundary users - who, whilst at the limit
    of being able to use the new product or service, advice on its
  • Expert users - who are experienced in
    rigorously reviewing products and services.

There are many different ways of involving users in the design process. They can be asked about their lives, what they want or need or what they think of the design. They may be observed in daily life to understand their experiences and needs. They can also participate as co-designers, providing direct input into the creative process.

Users may also be real or imaginary; whilst the involvement of real users adds particular richness to the design process, imaginary users, or personas, can provide a qualitative representation of user behaviour and bring users to life by giving them names, personalities and lifestyles. They identify the motivations, expectations, goals, capability, skills and attitudes of users, which are responsible for driving their product purchasing and usage behaviour. Although personas are fictitious, they are based on the knowledge of real users and may be described to suit the market segmentation adopted by an organisation.

Design Tools

Capability simulators are devices that designers can use to reduce their ability to interact with a product.Physical simulators can be worn to impair movement or vision, whilst software simulators modify an audio clip or photo image, so that someone who is fully able perceives the information as though he or she has a capability loss. These simulators can provide a quick and cheap method to help designers empathise with those who have capability losses, increase their understanding of the different losses, and simulate how exclusion occurs during product interaction. The cost, speed and ease of access means that these simulators can be used both early on and repeatedly throughout the design process (Clarkson et al., 2007).

Alternatively, an exclusion audit maybe undertaken to evaluate different products or concepts by comparing the proportion of the population that will be unable to use them. A task analysis is used to record the activities that are necessary to use the product, then the capability demands of these activities are assessed in terms of the levels of exclusion that result, allowing design decisions to be based on meaningful numbers.

Objective scales may also be used to measure the level of capability that a product or service demands in order to use it. Once the appropriate demand level has been identified, data from the 1996/97 Disability Follow-up Survey (Grundy et al., 1999) can be used to estimate the number of people that will be excluded (figure 5[3]). This in turn can highlight particular accessibility problems and corresponding opportunities for product improvement.

ceudconfpaper4-fig04Figure 5 - Objective scales can be used to measure capability demands


In conclusion, it is normal to be different. This places challenges on design commissioners and designers to specify and design products and services that are accessible to, and usable by, as many people as reasonably possible. Organisations that rise to this challenge will deliver better products and services that not only reduce exclusion, but also reduce difficulty and frustration to those who can already such products and services.

Inclusive design encourages a user-aware approach, where the potential of each design decision to exclude (or include) potential customers is accepted. Good design, based on such an understanding, has the potential to delight users with usable and accessible products and services, leading ultimately to the promise of commercial success.


  1. British Standards Institute (2005). British Standard
     Design management systems – Guide to managing inclusive
    . British Standards Institute, London, UK. Available from:
  2. Clarkson PJ, Coleman R, Hosking I and Waller S (eds.)
    (2007) Inclusive Design Toolkit. University of Cambridge, Cambridge,
    UK. Available from:
  3. Grundy, E., Ahlburg, D., Ali, M., Breeze, E. and
    Sloggett, A. (1999), Disability in Great Britain. Department of Social
    Security, Corporate Document Services, London, UK
  4. Keates S and Clarkson PJ (2003) Countering Design
    Exclusion, An Introduction to Inclusive Design. Springer-Verlag, London,
  5. Mace RL, Hardie GJ and Place JP (1991) Accessible
    Environments: Toward Universal Design. In Design Intervention: Toward a More
    Humane Architecture
    , Prieser WE, Vischer JC and White ET (eds.), Van
    Nostrand Reinhold, NY. Available
  6. Mynott C, Smith J, Benson J, Allen D and Farish M (1994)
    Successful product development: Management case studies. The Design
    Council, London, UK. Available from: M90s Publications, DTI, Admail 528, London
    SW1W 8YT.
  7. Philips (2004), The Philips Index: Calibrating the
    Convergence of Healthcare, Lifestyle and Technology
    . Philips Electronics
    North America, New York, NY. Available
    design/Design techniques/Inclusive design/Philips Index (US version).pdf
  8. UN (2004) World demographic trends. United
    Nations Commission on Population and development, New York, NY. Available from:
    demographic trends - N0463983.pdf

[1] Age demographic graph
showing half the adult population is over 45 years old.

Graph showing one-third find technological products easy, one-third are
frustrated, and one-third either have difficulty, or are excluded.

Graph showing the % of population who will be excluded from using a product or
service, depending on the demand level. Almost 3% of adults over 16 will be
excluded from low-demand products or services, and up to almost 6% from
high-demand products or services.