exercises

10. universal design

EXERCISE 10.1

Is multi-modality always a good thing? Justify your answer.

answer available for tutors only

The likely answer is yes. Multi-modal systems utilise more than one channel of information, which allows users to focus on more than one thing (for example monitoring via sound a background process while doing another task visually in the foreground). They support learning, since people learn better when more than one channel is used. They provide access for users with special needs without the need to develop special applications, so giving them access to wider work opportunities. They provide more interest and enjoyment leading to greater satisfaction. They avoid overloading one channel, by a cluttered screen, for example. On the negative side - multi-modality may require additional resources, it is not always needed, there is a danger of introducing multi-modality for its own sake.

 

EXERCISE 10.2

What are (i) auditory icons and (ii) earcons? How can they be used to benefit both visually-impaired and sighted users?

answer available for tutors only

(i) Auditory icons: use real-world sounds in structured ways to present information about objects and actions in the user interface. They rely heavily on the user making the associations between the sounds and the objects and actions they represent. Metaphors are used as the basis for these associations.

(ii) Earcons: use musical tones in structured sequences to present abstract information about objects and actions in the user interface. The individual tones are combined into motives, which are combined into earcons. These earcons can be single, compound or parallel.

Earcons and auditory icons can assist blind users in identifying screen objects. As they move the mouse over an object they hear its sound. The sounds can also be identified with actions, allowing blind users to choose the correct action - and can support navigation by providing positional information.

They can assist sighted users by providing redundant information for clarity and impact, by providing information when attention is focused elsewhere, and for confirmation of status and navigation.

 

EXERCISE 10.3

Research your country's legislation relating to accessibility of technology for the disabled. What are the implications of this to your future career in computing?

answer available for tutors only

The answer to this will depend on the country in which the student is working and the career they are pursuing. Relevant legislation in the UK includes the Special Educational Needs and Disability Act 2001 (SENDA), and the Disability Discrimination Act 1995 (DDA). In the USA the relevant legislation is the Americans with Disabilities Act 1990 (ADA). A document that outlines some of the implications in higher education, for example, is http://www.jisc.ac.uk/uploaded_documents/lis_disability.pdf. Issues such as equal access to information (e.g. on the internet or a company intranet) and equal access to necessary technology (e.g. ICT required for a particular job) are important.

 

EXERCISE 10.4

Take your university web site or another site of your choice and assess it for accessibility using [WEBAIM*]. How would you recommend improving the site?
* Note that the question in the book mentions Bobby, but the Bobby site is not longer online, use WEBAIM or AChecker instead.

answer available for tutors only

The answer to this question will depend on the web site chosen. Free online test services are available at http://wave.webaim.org/
and http://achecker.ca/checker/index.php. The report provided will give detailed advice about how to improve accessibility and the answer should be based on this.

For example, the second edition web site for this book produced the following report (on the old Bobby site):

Section 508 Accessibility
This page does not meet the requirements for Section 508 Approved status. Below is a list of 2 Section 508 accessibility error(s) found:

1. Provide alternative text for all images. (11 instances)
Lines 12, 23, 68, 75, 79, 83, 91, 96, 100, 106, 121
2. Explicitly associate form controls and their labels with the LABEL element. (1 instance)
Line 123

Section 508 User Checks
User checks are triggered by something specific on the page; however, you need to determine manually whether they apply and, if applicable, whether your page meets the requirements. Bobby Section 508 Approval requires that all user checks pass. Even if your page does conform to these guidelines they appear in the report. Please review these 7 item(s):

1. If you can't make a page accessible, construct an alternate accessible version.
2. Make sure that labels of all form controls are properly placed.
3. If you use color to convey information, make sure the information is also represented another way. (19 instances)
Lines 12, 15, 20, 23, 26, 32, 65, 68, 70, 75, 79, 83, 84, 91, 96, 100, 106, 121
4. If this is a data table (not used for layout only), identify headers for the table rows and columns. (2 instances)
Lines 9, 136
5. If there are logical groupings of form controls, use FIELDSET with LEGEND on each group. (1 instance)
Line 120
6. If an image conveys important information beyond what is in its alternative text, provide an extended description. (4 instances)
Lines 12, 68, 75, 121
7. If a table has two or more rows or columns that serve as headers, use structural markup to identify their hierarchy and relationship. (3 instances)
Lines 9, 61, 136
The following 1 item(s) are not triggered by any specific feature on your page, but are still important for accessibility and are required for Bobby Section 508 Approved status.
8. If a timed process is about to expire, give the user notification and a chance to extend the timeout.
Copyright © 2002 Watchfire Corporation. All rights reserved. Use of this software is subject to the Bobby Software License Agreement.

This example suggests two actions that are required to make the page accessible: adding "alt" tags to all images and using the "label" element in the form tag. All of the other recommendations are checks that should be made but which may not require any changes.

 

EXERCISE 10.5

How could systems be made more accessible to older users?

answer available for tutors only

Older people have a higher proportion of disabilities than younger people. Therefore the rules about making systems accessible to those with hearing, vision, speech and mobility impairments will assist older users who have age related disabilities. For example, the use of redundant information, flexible presentation style, captions, speech and sound are all important. In addition, text and audio communication tools can reduce problems of social isolation. However, although evidence shows that older people are not averse to using technology, they may be unfamiliar with the terminology and analogies that are prevalent. It is therefore important to provide sympathetic training and, where appropriate, design that takes account of the user's current understanding.

 

EXERCISE 10.6

Interview either (i) a person you know over 65 or (ii) a child you know under 16 about their experience, attitude and expectations of computers. What factors would you take into account if you were designing a website aimed at this person?

answer available for tutors only

The answer will depend on the data you gather from your chosen "user". What are their knowledge and skills? Have they used computers before and if so in what capacity? How do they feel about technology? Are they positive about the possibilities computers open up or not? What about their cultural background - what symbols and language are they familiar with? What about any disabilities or limitations? What do you consider to be the priorities of the person you have interviewed?

Your answers to these questions should identify the key factors that are important in designing something aimed at this individual.

 

EXERCISE 10.7

Use the Screen Reader simulation available at http://www.webaim.org/simulations/screenreader to experience something of what it is like to access the web using a screen reader. Can you find the answers to the test questions on the site?

answer available for tutors only

This is an experiential exercise, giving the user an idea of what it is like using a screen reader. The intention is that you try out the simulation and attempt to answer the test questions provided on the site. If you can do so easily it suggests that the site is reasonably accessible. If not then this is the frustration a visually impaired user would have.

 

EXERCISE 10.8 [extra - not in book]

In this chapter, we look at alternative interfaces for users with special needs. How could standard interface design be improved to provide better access to these users?

answer

This depends on the particular needs of the user, but in general the more an interface relies on a single channel (such as the visual channel) for information the more likely it is to be unusable by some people.

Multi-modality and redundancy in the interface will alleviate this problem by providing alternative views of the information and so not excluding a user group with restricted use of the primary channel.

It is more satisfactory to encourage multi-modality as a design principle than to provide special systems or 'add-ons' to cater for extra-ordinary user groups. This can also benefit the average user since it reinforces the information over several channels.
However, this may not be possible in all cases: clearly, for example, a user who has limited control of hands and voice may need special equipment such as the Eyegaze system which will track eye movements. Where possible such specialized equipment should be integrated with standard applications to enable the disabled user to use readily available machines and software in common with other users. This is particularly important in the work environment.

 

EXERCISE 10.9 [extra - not in book]

Consider a user with limited hand coordination, or one with poor eyesight. It is clear that typical computer systems, with their reliance on hand-eye coordination and highly detailed visual output, disadvantage such people. List a number of devices that have been developed to assist users with special needs, identifying whether they assist the user in achieving the same sort of interaction as a non-special-needs user, or whether they adapt the computer explicitly to help the person concerned and so move away from the keyboard+mouse+screen style of interaction.

answer available for tutors only

Devices include:

  • Reactive keyboard: same interaction
  • Eye gaze: different interaction
  • Keyboard driver: same interaction
  • Braille output: different interaction
  • Haptic devices: different interaction
  • Speech/sound: different interaction

 

EXERCISE 10.10 [extra - not in book]

Why did the widespread introduction of GUIs reduce the accessibility of computer systems to visually impaired people?

answer available for tutors only

Prior to the introduction of GUIs visually impaired users had access to command based textual interfaces through the use of screen readers and Braille input/output devices. Most visually impaired users can touch type so keyboard input not a problem. When GUIs were introduced navigation around the interface became impossible as user could not see the icons/menus and screen readers cannot read a graphical screen. In addition users with problems with hand-eye co-ordination may find using pointing devices more difficult to use than text based interfaces (particularly aided by a reactive keyboard). Increasing use of multimedia and audio channels has implications for deaf users.

Individual exercises

ex.10.1 (tut), ex.10.2 (tut), ex.10.3 (tut), ex.10.4 (tut), ex.10.5 (tut), ex.10.6 (tut), ex.10.7 (tut), ex.10.8 (ans), ex.10.9 (tut), ex.10.10 (tut)

Worked exercises in book

  

Think of a set of naturally occurring sounds to represent the operations in a standard drawing package (for example, draw, move, copy, delete, rotate). [page 378]

  
  • a worked exercise
  
  • a worked exercise
  
  • a worked exercise