Broadly defined, a webcast is the use of the Internet to broadcast a meeting or event. Webcasts are often broadcast live, but may additionally be recorded for subsequent viewing. Educational entities use webcasts to host online lectures, meetings, and other events.
Webcasts vary significantly in their level of audience interactivity. Some webcasts simply involve one-way communication in which an instructor delivers a lecture to an audience using streaming media over the Internet. However, webcasts can also involve a great deal of interactivity. A growing number of vendors provide feature-rich webcast services in which audiences can submit questions to instructors or chat privately with other audience members; instructors can poll or quiz audiences and display instant graphs showing the results; and instructors can supplement their lectures with slides or share their computer desktop in order to deliver software demonstrations. These are only a few of the many interactive features that are possible with webcasts.
The potential for accessibility barriers grows with the complexity of the webcast environment that's being utilized. To evaluate the accessibility of a webcast product or service, all of the Electronic and Information Technology Accessibility Standards  developed by the Access Board (in response to Section 508 of the Rehabilitation Act, as ammended in 1998) for web accessibility, software accessibility, and multimedia might be applicable.
Following are a few examples of the types of accessibility-related questions that educational entities should ask when considering a webcast product or service:
- Does the webcast product or service support captioning for participants who are deaf? If so, can the captioning window be moved and resized? Can the font size or color of the caption text be changed?
- Are all features accessible by the keyboard alone? Some users are unable to use a mouse.
- If all features are accessible by keyboard, are they also compatible with screen readers? Some products, even if accessible by keyboard, do not provide screen readers with essential information about interface compontents. Therefore, screen reader users may be able to navigate through the webcast environment, but they'll be completely lost without dependable audible feedback.
- If the webcast environment is generally accessible to screen reader users, how are these users notified when content changes dynamically? For example, if the instructor advances to the next slide, or if a participant receives a private chat message from another participant, how is the screen reader user made aware of this information?
- Are there features that communicate information exclusively using color? If so, these features will be inaccessible to users who are unable to perceive color differences. For example, some webcast products include audience seating charts in which audience members can change the color of their seats to send messages to the instructor such as "Slow down" or "Speak up". If the instructor is color blind, they will be not receive this important feedback.
- Is the webcast environment customizable? Given the complexity of many webcast environments, participants with cognitive or learning disabilities can become easily distracted and may benefit from closing windows or disabling features. Participants using screen magnification software might also benefit from being able to rearrange their environment for optimum display on an enlarged screen.
Currently, no webcast product or service providers can respond affirmatively to all of the questions above. However, by asking these questions, educational entities can identify which products are somewhat accessible versus those that are totally inaccessible. Also, asking these questions sends the message to vendors that customers consider accessibility in purchase and use decisions and guides them on specific accessibility issues they should begin to address.
In addition to asking questions such as these when procuring a webcast product or service, individual instructors or meeting hosts should be aware of these same issues when delivering a webcast, and should utilize only those features that do not exclude audience members.
In some cases, audience members with disabilities may be accommodated by providing equivalent alternatives to inaccessible features. For example, if a webcast product provides a means by which audience members can electronically submit a question to the instructor, and that feature is not accessible to keyboard users, questions can additionally be accepted by email or phone, as long as questions are answered with equal efficiency regardless of the mode in which they were delivered.
Similarly, if an instructor is supplementing their presentation by showing slides, these slides are probably inaccessible to screen reader users, since most webcast products display slides as images with no text equivalent. To make slide content accessible, instructors should clearly verbalize the content of each slide, just as they should in a face-to-face lecture. Slide content should also be made available in an accessible format, with sufficient lead time prior to the event so that audience members can download it.
In many ways, webcasts represent the ultimate in information technology in education. They utilize a variety of technologies including the web, software, and multimedia, and allow students to be engaged in learning despite geographic barriers. In order for all learners to have equal opportunities to benefit from this rich learning environment, vendors must develop more accessible products, education administrators must purchase only those products that attempt to address accessibility, and instructors must use only those features that are accessible or be prepared to provide accommodations to participants who face access barriers.
-  Electronic and Information Technology Accessibility Standards