Thousands of specialized hardware and software products available today allow individuals with a wide range of abilities and disabilities to productively use computing and networking technologies (Closing The Gap , 2002). However, assistive technology alone does not remove all access barriers. Described below are examples of access challenges faced by students and instructors in typical distance learning courses.
A student or instructor who is blind may use a computer equipped with screen reader software and a speech synthesizer. Basically, this system reads with a synthesized voice whatever text appears on the screen. He may use a Braille refreshable display that prints screen text line by line. He can use a text-only browser to navigate the World Wide Web or simply turn off the graphics-loading feature of a multimedia web browser. He cannot interpret graphics (including photographs, drawings, and image maps) unless text alternatives are provided. Printed materials, videotapes, televised presentations, overhead transparencies, and other visual materials also create access challenges for him. These barriers can be overcome with alternative media such as audiotapes, Braille printouts, electronic text, tactile drawings, and aural descriptions.
Other Visual Impairments
A student or instructor who has limited vision can use special software to enlarge screen images. He may see only a small portion of a web page at a time. Consequently, he can easily become confused when web pages are cluttered and when the page layout changes from page to page. Standard printed materials may also be inaccessible to him; he may require large print or electronic text. Individuals who are color-blind cannot successfully navigate web pages that require the user to distinguish colors.
Specific Learning Disabilities
Some specific learning disabilities impact the ability to read, write, and/or process information. A student with a learning disability may use audiotaped books. To help her read text efficiently, she may also use a speech output or screen enlargement system similar to those used by people with visual impairments. She may have difficulty understanding websites when the information is cluttered and when the screen layout changes from one page to the next.
A student or instructor with a mobility impairment may not be able to move his hands; he may use an alternative keyboard and mouse or speech input to gain access to Internet-based course materials and communication tools. Another student or instructor may be able to use standard input devices but may lack the fine motor skills required to select small buttons on the screen. If his input method is slow, a person with a mobility impairment may not be able to effectively participate in real-time "chat" communications. If any place-bound meetings are required in a distance learning course, a participant with a mobility impairment may require that the location be wheelchair-accessible.
Most Internet resources are accessible to people with hearing impairments because these resources do not require the ability to hear. However, when websites include audio output without providing text captioning or transcription, a student who is deaf is denied access to the information. Course videotapes that are not captioned are also inaccessible to this student. He may also be unable to participate in a telephone conference or videoconference unless accommodations (e.g., sign language interpreters) are provided for that part of a distance learning course.
A student with a speech impairment may not be able to effectively participate in interactive telephone conferences or videoconferences. However, modes of participation that do not require the ability to speak, such as electronic mail, are fully accessible.
Some attention-grabbing features of web pages include flickers. Flickers at certain rates (often between 2 and 55 hertz) can induce seizures for people who are susceptible to them.
For more information, consult Technology and Universal Design  and Real Connections: Making Distance Learning Accessible to Everyone  or view the video  by the same title.
-  Closing The Gap
-  Technology and Universal Design
-  Real Connections: Making Distance Learning Accessible to Everyone
-  view the video