1 Accessibility: an introduction
1.1 What is accessibility?
In this unit we will focus on the accessibility of interactive products.
Much of the information in these sections on disability comes from the DEMOS project, a project which ran from 2000 to 2003, funded by the Higher Education Funding Council for England with a view to improving higher education provision for disabled students.
The term accessibility normally refers to the degree to which an interactive product is useable by disabled people. It should be noted that one survey found that a significant proportion of the adult UK population – about 14 per cent – is disabled, so widening accessibility to include disabled people might involve a considerable increase in the number of people who can use a particular product.
In Section 2 we will discuss what we mean by ‘disability’. For example, which, if any, of the following people would you consider disabled?
- A woman on crutches because she broke her leg a couple of weeks ago, though it is now healing nicely.
- A woman with sight problems such that she has no three-dimensional vision, and hence no judgement of distances, and so is unable to drive. (This is actually my own situation.)
- A man who is too deaf to hear normal conversation unaided but who has just been fitted with a hearing aid which enables him to converse without difficulty.
- A man with schizophrenia who has to take daily medication which makes him very tired and unable to concentrate for long periods of time.
I will answer this and other questions in Section 2.
In Sections 3–6, I will delve deeper into some common impairment and disability groups, considering people with visual impairments in Section 3, with hearing impairments in Section 4, physical impairments in Section 5, and dyslexia and other cognitive impairments in Section 6. In each of these sections I will briefly describe the relevant impairments and how they might affect a person's use of interactive devices. Where relevant, I will describe some common assistive technologies. These technologies, as their name suggests, assist people with impairments to interact with computers. We then discuss the requirements that each disability group might have for computers, and for other interactive products.
You should be aware that this division of the material does not reflect the complexity of the subject. For example, it does not take into account the following facts:
- Disabled people can have a range of impairments, and more than one impairment at the same time.
- Each impairment can vary both in severity and in the impact it has on a person's life.
- This severity and impact can vary over the course of a day (for example, as people get tired) and over the course of a lifetime (for example, many people notice a deterioration in their eyesight and hearing as they get older), and with respect to the activities being done (for example, fine embroidery needs better eyesight in some sense than watching a movie).
The aim of Sections 1–6 is not for you, having read these sections, to be able to say ‘A person has X and this has Y implications for interaction design’. Rather, I hope to raise your awareness of the issues, for example, through the use of simulations to give you a little insight of what it feels like to have a disability (though I appreciate that some of you may already have the relevant disability and hence have no need of any simulation); to inform you of current thinking on how the issues might be addressed, and to emphasise, yet again, how important it is to know your users and involve them (if at all possible) in every stage of interaction design.
Let's begin by discussing the reasons why all interaction designers should be concerned with widening accessibility to their product to disabled people. There are three main factors which contribute to these reasons: ethics, good practice and the law.
Regarding ethical issues, disabled people have the same rights as non-disabled people to access goods and services. From an ethical standpoint therefore, disabled people should not be excluded from using any product, device or service if it is at all possible to avoid it.
The second factor is that it is good commercial practice to make a product available to as wide a market as possible. In addition, a design that takes account of the requirements for disabled people is likely to be more accessible and useful for non-disabled users. For example, a user interface that is usable by a blind person will also be usable by a person whose eyes are busy, for example, people who are doing a task that requires visual concentration, such as driving a vehicle or operating machinery such as a crane, or who cannot interact visually because they are using a service via the telephone.
Suppose you have designed an interactive product specifically for people who have impaired use of their hands. In what contexts of use might this facet of the design be useful for people who have unimpaired use of their hands?
I think the fact that the product has been designed for people with impaired use of their hands will be useful for people with unimpaired hand use, when the latter have their hands full (with, for example, shopping or a baby) or when they are simultaneously doing another task which needs hands – typing on a computer keyboard, for example.
A third factor that necessitates the consideration of disabled people's needs is that of legal obligation. In the UK, in 1995, the Disability Discrimination Act (DDA) made it unlawful to discriminate against disabled people as employees, as students, and as consumers of goods and services. Under the act, employers, education establishments, and providers of goods and services need to make ‘reasonable adjustments’ to avoid discriminating against disabled people.
In practice the DDA means that, where ‘reasonable’, websites, software, buildings and other entities involved in employment, education or other services, need to be made accessible. An important aspect of the Act is that the needs of disabled people should be anticipated rather than waiting for a disabled person to need access. This means that a provider of a service cannot justify not making an adjustment by saying that they do not have any disabled customers; they need to anticipate that they may have disabled customers in the future. This is a key aspect for interaction design as it means that if there is any chance of members of the user group being disabled, then action must be taken to take their needs into account. This underscores the importance of understanding your users and their goals. While it is true that some occupations may lead to the conclusion that it is acceptable to assume certain characteristics of your users, there are very few occupations where it would be safe to assume no disability.
The following activity is designed to stimulate you to think about what ‘reasonable’ means in the context of the DDA.
These examples are adapted from a government website. You can access the site by clicking here, then click on the ‘Disability Discrimination Act’ (accessed on 27 November 2006).
Decide whether the following are ‘reasonable’ in the context of the DDA:
- A video rental shop insists on seeing a driving licence as a proof of identity before allowing anyone to become a member.
- A nightclub insists on using low-level lighting throughout despite the fact that this does not make provision for partially sighted people.
- A shop has a policy of not allowing any dogs on its premises.
- Customers in a busy sub-post office are required to stand in a queue to be served. A disabled customer with severe arthritis wishes to purchase a television licence but experiences great pain if he has to stand for more than a couple of minutes. He thus requests that the post office send a member of staff to his home to sell him the licence.
- A small business has two employees and a boss. The boss refuses, on grounds of cost, to install wheelchair access, for which there is currently no need.
- This is unreasonable – it precludes anyone with a disability which stops them driving (like me) from becoming a member. It would be easy for the shop to ask for alternative means of identification.
- This is reasonable – low-level lighting is an essential part of the ambience of a nightclub.
- Unreasonable – surely the shop would be as happy to take the money of blind as well as of sighted customers. Exceptions should be made for guide (and hearing) dogs.
- The request from the customer is unreasonable. Requesting the provision of a chair in the sub-post office would be reasonable.
- The boss's refusal is reasonable given her small number of employees.