MAR 21 2012

Accessibility of software programs and web services

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This article provides information on user-friendliness, or accessibility, for users with a broad range of skills, i.e. for people with the widest range of physical, sensory and cognitive abilities, including those who are temporarily disabled, and the elderly. I am pleased with this definition, which has been taken from the standard ISO 9241-171 for ergonomics guidance and specifications for the design of accessible software for use at work, in the home, in education and in public places. It covers issues associated with designing accessible software for people with the widest range of physical, sensory and cognitive abilities, including those who are temporarily disabled, and the elderly.

Should you ever need a guide to conduct a tour group through an entirely dark environment, I’m at your disposal. I am completely blind. I can also show you how to use software without a screen – but only when the software in question meets accessibility standards of course.

“Accessibility is the usability of the interactive user interface of a product, service, environment or facility by people with the widest range of capabilities” (ISO 9241-171, definition 3.2).

But first things first: I realize that, having lectured at the university for so long, I tend to use too many general definitions and gobbledygook! So from now on, first things first, in simple and comprehensible terms:

Examples for accessibility
I will attempt to illustrate accessibility in the following three examples. As you will see, it is not limited to people with special needs.

Example 1: I, a blind user of MS Outlook
The trick is that all functions in MS Outlook can also be performed with the keyboard.

  • CTRL +1 is the shortcut to the mail list
  • CTRL+2 to the calendar
  • In all lists the arrow keys enable me to move between objects
  • I can open the focused entry with the Enter key, delete with the Delete key, etc.
  • And I can do it all very fast.

Example 2: Inge in the Internet
Inge gets tremors, e.g. her hands tremble and she has problems positioning the mouse exactly. However, an accessible Internet site makes her feel efficient and satisfied: the buttons are of a sufficient size and spaced well apart. She is able to activate ONLY the options she wants to and doesn’t lose time and patience trying to aim correctly.

Example 3: A driver using a browser
This is still science fiction: Fritz is a truck driver and constantly on the road. He likes to read Wikipedia articles for entertainment. While on the road, Fritz uses his hands and eyes exclusively for driving. He operates the Internet browser with verbal commands and listens to the language editions of the entries. The site must have a high level of accessibility.

Who profits from accessibility?
The user profiles that profit from web and software accessibility vary considerably:

  • People with limited motor skills
  • People with limited sensory skills (blindness, deafness, impaired hearing, visual impairment)
  • People with cognitive impairments and learning difficulties
  • People with temporary impairments (e.g. with a fractured arm)
  • People in specific situations or environments (driving a vehicle, working in a loud factory)
  • Search machines (as special virtual users).

What makes software / web content accessible?
A very good summary of the necessary measures is found in the document Web Content Accessibility Guidelines (WCAG) 2.0 by the working group Web Accessibility Initiative (WAI) of the W3 consortium.

All content and elements of the user interface (buttons, selection boxes etc.) must be perceivable, operable and comprehensible.

The following presents a number of selected user cases for these three main categories.

Content is perceivable
The perception of all content that is not strictly text related is always subject to sensory skills. A blind person cannot see images, a deaf person cannot listen to the audio track of a video.

The appropriate solution for these problems consists in alternatives that are equivalent to the non-text related content. For instance, the paper basket icon is supplemented with the alternative text “paper basket”. This enables assistant technologies such as screen reader software to interpret the function behind the icon and to read the text, or issue it as a Braille line.

Subtitles are a suitable alternative to the audio track. Thereby the text must capture all items of dialogue and allocate them to the respective speaker, including all relevant sounds (doorbell, telephone etc.).

All functions are operable
Most users operate software and websites with a mouse. For blind, visually impaired or motor impaired users this is highly inefficient, if not impossible. Operability requirements for software demand that all functions can also be utilized with keyboard commands, if the supported appliance possesses a keyboard. Mobile touch-screen devices must additionally implement an amended operational logic enabling intuitive usage with screen reader software. The iPhone and iPad, with the integrated ScreenreaderVoiceOver, are wonderful examples of successfully implemented accessibility at the appliance level.

Comprehensible content and user interface
The importance of comprehensible content as an accessibility requirement varies according to the group of users.

For users of screen reader software this mainly implies that the software reads the content correctly in different languages. CORRECTLY means in the language setting of the selected language.

For persons with cognitive impairments, comprehensible means that the texts are easy to read. The main characteristics of easily readable texts are:

  • short sentences
  • using active instead of passive forms
  • focussing only on one idea per paragraph
  • using a minimum of abbreviations and (this is essential) explaining all abbreviations when used for the first time

Accessible software, web content and documents also enable us, users with a broad range of skills, to work in a satisfactory, sufficiently productive and efficient way.

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Related posts:

  1. Guidelines and directives on accessibility


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