Part 5: Perceptible Information, the fourth principle of Universal Design
by Antonia Levy, Christopher Leydon & Chris Kchao
This month we discuss the fourth principle of Universal Design (UD), Perceptible Information, meaning that “the design communicates necessary information effectively to the user, regardless of ambient conditions or the user’s sensory abilities.”
Guidelines for adherence to this principle include:
- Use different modes (pictorial, verbal, tactile) of presentation for essential information.
- Provide adequate contrast between essential information and its surroundings.
- Maximize “legibility” of essential information.
- Differentiate elements in ways that can be described (i.e., make it easy to give instructions or directions).
- Provide compatibility with a variety of techniques or devices used by people with sensory limitations.
Practical examples for this principle are tactile features on numeric keypads for blind users, which usually include a dot on the 5 key, a tactile circle on the enter/confirm button and a tactile x on the cancel/clear button. Consumer devices such as thermostats or infrastructure such as pedestrian signals now employ a combination of tactile, visual, and audible cues to be accessible to all.
In education, this principle calls for providing essential information in a variety of modes (e.g., written, symbolic, tactile, verbal) thereby ensuring effective communication with all users regardless of their sensory abilities. This includes making all (online) instructional materials accessible to users of screen reading software as demonstrated in this video.
For an expert account of how screen readers, we turned to guest contributor Chris Kchao, who handles assistive technology in the Office of Student Disability Services here at CUNY SPS.
Screen readers, sometimes referred to by the general term screen access programs, allow blind or visually impaired users to gain access to written information on electronic devices. Text is typically either read aloud by a synthetic voice or output to a refreshable Braille display. The function of a screen reader is not simply to render any text available on screen, but to facilitate interaction between the person and the user interface. In practical terms, the screen reader doesn’t just voice the text, but also provides contextual information about the item being read (whether it’s a menu, button, checkbox, link, etc). For instance, here’s the output from the NVDA screen reader when a user presses the Windows start key:
Start menu, Search Box, edit: Search programs and files.
By way of these prompts, a user is informed not only of what the screen says, but also how to proceed. Among other things, we’re told that a menu is present, and that we’re focused on an edit field in which we may begin entering text.
When a screen reader encounters a document embedded on a website or posted in a Blackboard course site and the user opens it, that document also needs to be accessible to the screen reading software in order for a visually impaired person to access the content. PDF documents, for example, are only accessible when text contained in them is searchable. They should include other “hidden” features, called tags that are added for accessibility purposes only and have no visible effect on the PDF. Such tags include descriptive text for images (called Alt Text) or structure tags (called headings) added to titles, subtitles, etc.
Note that most PDFs created using a scanner are considered inaccessible because they are simply images of the page, which means that a screen reader cannot recognize any of the text. For various ways to make PDF documents accessible to all, see our quick guide or video tutorial with detailed instructions.
PDFs may also be created by conversion from another type of file, such as Word or PowerPoint. If you follow accessibility guidelines when creating those source documents, and then “save as” a PDF, the accessibility features such as headings or Alt Text for images will carry over into your PDF document. See our Accessibility Resources Site for additional tutorials explaining how to create accessible Word, Excel, and Powerpoint documents as well adding captions to your YouTube videos.
This article is part of an ongoing series introducing the concept of Universal Design (UD) as it applies to the context of higher education and to our work at CUNY SPS. Each installment covers one of the seven principles of UD with practical examples for both faculty and staff, including things you might not immediately associate with accessibility—or inaccessibility. Catch you next time!
Questions or feedback? Email Antonia Levy or Christopher Leydon.