The kiosk's screen reader interprets content on the kiosk using text to speech. In order for the screen reader to give an effective user experience, kiosk content that is presented in images and thumbnails will require alternative text, an equivalent way of communicating non-text content that an application such as a screen reader can access it. This should be used combination with using semantic HTML that allows the kiosk screen reader to accurately determine document structure.
Whenever there is a change in kiosk content, for example, when a new themed tour is added to the kiosk's roster, care should be taken to include alt text descriptions for any visual content that is added. This is a very fast and simple way to maintain the kiosk's accessibility.
A text alternative should be brief but as informative as possible so that it can support the kiosk's purpose of introducing visitors to the themes of the DIA, and then getting them on their way to the galleries. Here is a heuristic process for creating alt text:
Identify the images, and for each image, consider the following questions:
- Why is this non-text content here?
- What information is it presenting?
- What purpose does it fulfill?
- If I could not use the non-text content, what words would I use to convey the same function and/or information?
In a nutshell, the text alternative should be able to substitute for the non-text content. One can imagine what it would be like if the kiosk didn't feature any images or icons at all, but instead was only text. How could the kiosk still provide the same function and information to a visitor?
It is also important to have the kiosk evaluated from the point of view of a screen reader user to determine the effectiveness of the ALT texts and adapt them if necessary.
Please see our Kiosk wireframes (Draft 5) and their associated storycards for examples of how alt text is integrated.