CM143 - Web Week 11 Accessibility Priority Checkpoints

Accessibility vs Usability Usability catalogues the ways in which the user experience may be improved and simplified – Focuses on criteria such as navigation, sense of position in a site, etc. Accessibility refers to the actual ability of users to access the information in a site, which in some cases may be impossible – Focuses on provision of text equivalents, suitability of language, limitations of layout, etc

Priority Checkpoints Priority 1: Developer must satisfy this checkpoint. Otherwise, one or more groups will find it impossible to access information in the document. Satisfying this checkpoint is a basic requirement Priority 2: Developer should satisfy this checkpoint. Otherwise, one or more groups will find it difficult to access information. Satisfying this checkpoint will remove significant barriers to accessing Web documents. Priority 3: A Web content developer may address this checkpoint. Satisfying this checkpoint will improve access to Web documents

Priority 1 Checkpoints Provide a text equivalent for every non-text element (e.g., via "alt", "longdesc", or in element content). – This includes: images, graphical representations of text (including symbols), image map regions, animations (e.g., animated GIFs), applets and programmatic objects, ascii art, frames, scripts, images used as list bullets, spacers, graphical buttons, sounds (played with or without user interaction), stand-alone audio files, audio tracks of video, and video.

Priority 1 Checkpoints Ensure that all information conveyed with colour is also available without colour, for example from context or markup. – Applies to information organisation reliant on coloured headings, codes, or backgrounds which may not be perceptible to the visually impaired, the colour-blind, or certain rendering software

Priority 1 Checkpoints Clearly identify changes in the natural language of a document's text and any text equivalents (e.g., captions). – This is necessary for screen readers to accommodate changes in the produced speech when reading the information

Priority 1 Checkpoints Organize documents so they may be read without style sheets. – For example, when an HTML document is rendered without associated style sheets, it must still be possible to read the document. – Separation of content and styling

Priority 1 Checkpoints Ensure that equivalents for dynamic content are updated when the dynamic content changes. – Applies to content loaded when the page is refreshed or first loaded (usually from a database) – PHP, ASP etc

Priority 1 Checkpoints Until user agents allow users to control flickering, avoid causing the screen to flicker. – Avoid over-use of animation, particularly GIFs with a high frame rate – Avoid frequent full page refreshes

Priority 1 Checkpoints Use the clearest and simplest language appropriate for a site's content. – Avoid unnecessary verbosity or extensive use of technical terms and jargon where they are not referenced or assumed well known by the target audience