Introduction to Accessibility

Accessibility allows people to use a product or service even when they are using it under conditions that limit or inhibit their abilities. In this context, limiting conditions may be functional or situational:

• Functional limitations pertain to disabilities, such as blindness or limited use of the hands. Functional limitations can be visual, auditory, physical, or cognitive (which is very broad and includes aspects such as language and learning disabilities). Functional limitations can be temporary or permanent.
• Situational limitations relate to the circumstances, environment, or device. These limitations can affect anybody, not just people with disabilities. Examples include trying to carry on a cell phone conversation in a noisy environment or trying to use a handheld personal digital assistant (PDA) when you have a sprained thumb.

When a product or service is accessible, its user interface is understandable and operable by people operating with functional or situational limitations.

When a product or service is designed to accommodate functional limitations, oftentimes the benefits of that design transfer to those who are operating with situational limitations.

Making Technology More Accessible

There are two primary ways to make technology accessible: (1) build accessibility directly into the "mainstream" product or service, and (2) make the "mainstream" product or service compatible with assistive technology.

Accessibility that is built into a "mainstream" product or service can take many forms:

• If a software application allows a user to navigate and use its functionality strictly through use of keyboard shortcuts (instead of or in addition to the "pointing and clicking" of a mouse), then this feature is an example of built-in accessibility. In this case, this accessibility feature helps people who are blind because they cannot see where they should point the mouse. It also helps people who have tremors or arthritis in their hands; they may not have the fine motor control that is needed to point and click a mouse button.
• If an operating system allows a user to set his or her preferences for text and icon sizes and for color schemes and contrast, then these capabilities would be considered accessibility that is built into a "mainstream" product. Users who have low vision benefit greatly when they can increase the size of text and icons that appear on displays, such as computer monitors or cell phone screens. Many users with low vision also find it easier to read white text on a black background; some operating systems allow them to change their system defaults to match their preferences.

In some cases, it can be very difficult or impossible to make a "mainstream" product or service directly accessible to someone with a disability. In this case, a product designer can provide access to the "mainstream" technology by making it compatible with assistive technology.

Following are some examples of assistive technology (or AT) that are commonly used by people with disabilities:

• On-screen keyboards are software images of a standard or modified keyboard placed on the computer screen by software. The keys are selected by a mouse, touch screen, trackball, joystick, switch, or electronic pointing device. [1]
• A screen reader is a software program that works in conjunction with a speech synthesizer to verbalize everything displayed on a screen including control buttons, menus, text, and punctuation. [2]
• A screen enlargement program focuses on a single portion of the screen and enlarges it. [3]
• A teletypewriter (or TTY) is a device with a keyboard that sends and receives typed messages over a telephone line. [4]

The Assistive Technology Industry Association (or ATIA) developed AT-IT Compatibility Guidelines that are meant to help mainstream IT vendors make their products and services compatible with current and future assistive technologies.

Learning More

If you want to learn more about accessibility, check out these resources:

• Accessibility and the User-Centered Design Process, from ITTATC, which defines accessibility (and usability) and explains how accessibility can be incorporated into the product design process.
• Guidelines for the Design of Consumer Products to Increase their Accessibility to Persons with Disabilities or Who are Aging, from the Trace Center, which presents design guidelines for consumer products such as appliances and other electronic and mechanical devices available to the mass market for use in the home, school, office, or for use by the general public in the community.
• Designing More Usable Telecommunications, from the Trace Center, which is a list of key resources, documents, and programs related to making telecommuniations more usable for all.
• Getting Started: Making a Web Site Accessible from the World Wide Web Consortium (W3C), which explains why web accessibility is needed, what makes a website accessible, and how to evaluate websites for accessibility.
• The Technology Toolbox by the Alliance for Technology Access (ATA), which provides a description of many different types of assistive technology as well as some software features that are generally desirable to people with disabilities.
• Assistive Technology Quick Reference Series by Tech Connections, which offers frequently asked questions (and answers) about specific types of AT. The series also provides links to other information resources and to vendors that sell the AT.

References

1. Alliance for Technology Access (2001). Alternate Keyboards. Computer and Web Resources for People with Disabilities. http://www.ataccess.org/resources/atabook/s02/s02-03a.html.
2. Alliance for Technology Access (2001). Screen Readers. Computer and Web Resources for People with Disabilities. http://www.ataccess.org/resources/atabook/s02/s02-05e.html.
3. Alliance for Technology Access (2001). Screen Enlargement Programs. Computer and Web Resources for People with Disabilities. http://www.ataccess.org/resources/atabook/s02/s02-05f.html.
4. Alliance for Technology Access (2001). TTYs and TTY Modems. Computer and Web Resources for People with Disabilities. http://www.ataccess.org/resources/atabook/s02/s02-06f.html.