Commonly Used Terms in Web Accessibility


Accessible web content is usable by all people, regardless of physical or developmental abilities or impairments. Web accessibility uses the principle of universal design to make websites, applications, and content that is usable by persons with disabilities who may or may not be using assistive technologies to access the site.

Alternative Text (Alt Text)

Screen readers require descriptions of all graphics (photographs, charts, or other images) to be added by the author of the website or document. This description is called alternative (alt) text. When a screen reader reaches an image on your page or document, it will read out loud the description you have added. Alt text allows a user of a screen reader to get a sense of what that image is and it’s purpose in context.

Assistive Technology

Any device (item, piece of equipment, software, or system) used to increase, maintain, or improve the functional capabilities of a person with a disability. This include screen readers, head and mouth wands, speech recognition software, adaptive keyboards, eyetracking systems, etc.


Captions are text versions of the spoken words presented within multimedia. Captions allow the content of web audio and video to be accessible to those who do not have access to audio.

Common web accessibility guidelines indicate that captions should be:

  • Synchronized — the text content should appear at approximately the same time that audio would be available

  • Equivalent — content provided in captions should be equivalent to that of the spoken word

  • Accessible — caption content should be readily accessible and available to those who need it

On the web, synchronized, equivalent captions should be provided any time multimedia content (generally meaning both visual and auditory content) is present. This includes video and PowerPoint presentations that include audio.

Captions can be either closed or open. Closed captions can be turned on or off, whereas open captions are always visible.

Cognitive Impairment

A person with a cognitive deficit or impairment has trouble remembering, learning new things, concentrating, or making decisions that affect his or her everyday life. Cognitive impairment ranges from mild to severe.


When encountering a lengthy web page or document, sighted users often scroll the page quickly and look for big, bold text (headings) to get an idea of the structure and content of the page. Users of assistive technology also have the ability to navigate web pages by heading structure, assuming true, pre-formatted headings are used (as opposed to text that is styled to be big and/or bold). This means that the user can view or hear a list of all of the headings on the page, or can read or jump by headings, or even navigate directly to top level headings or headings that are lower in the hierarchy (subheadings).

Web pages and documents should be structured in a hierarchical manner, see nesting.

Motor Impairment
The partial or total loss of function of a body part, usually a limb or limbs. This may result in muscle weakness, poor stamina, lack of muscle control or total paralysis.

Nesting refers to the hierarchy of headings in a page structure or a list of items. Web pages and documents should be structured in a hierarchical manner, generally with one 1st degree headings being the most important (your site name or document title), then 2nd degree headings (your page title on the CMS or the major section headings of your document), followed by 3rd degree headings (sub-sections of your web page or subsections of the major section headings of your document), and so on. Lower degree headings should be contained within headings of the next highest degree (i.e., one should not skip heading levels, such as from a Heading 2 to a Heading 4, going down the page or document).

The following outline shows an example of such a hierarchy:

Language Studies - 1

Asian Languages - 2

Chinese - 3

Japanese - 3

Germanic Languages - 2

Danish - 3

German- 3

Slavic Languages - 2

Czech - 3

Polish - 3

Russian - 3

Screen Reader
Users with severe visual impairment may rely on a screen reader to access websites. A screen reader is a software program that takes the on-screen text and reads it out loud to the user. Visual cues, such as photographs, graphics, or table headers, may be unperceivable to this audience unless additional information is added (text alternatives for images “alt text” and other visual content and the specification of key landmarks, e.g. headings and lists, within a document). VoiceOver for Apple is the screen reader primarily used on this campus. If you have a MAC, you can turn your built-it screen reader VoiceOver on or off by pressing command+F5. Try out a screen reader simulator.

Transcripts allow anyone that cannot access content from web audio or video to read a text version instead. They also allow the content of your multimedia to be searchable, both by computers (such as search engines) and by end users.

Descriptive transcripts include additional information about what is heard in the video. They should contain additional descriptions, explanations, or comments that may be beneficial, such as indications of laughter or an explosion.

Universal Design

Universal design (also barrier-free or inclusive design) refers to design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design. Elements that have been universally designed are inherently accessible to older people, people without disabilities, and people with disabilities.


WCAG (Web Content Accessibility Guidelines) is a set of web accessibility guidelines published by the W3C, which is the main standards organization for the World Wide Web. WCAG is the most widely adopted standard for creating accessible web content. At Brandeis, we strive to meet the standards of web accessibility known as WCAG 2.0 AA.


WebAIM (Web Accessibility In Mind) is one of the leading providers of web accessibility expertise internationally. WebAIM is a non-profit organization based at the Center for Persons with Disabilities at Utah State University.