EN: Eine für Smartphones optmierte Version wird in Kürze verfügbar sein
4.0.Usability    4.2.Accessibility


Accessibility is in ISO / TS 16071 (ISO, 2003) an extension of usability: "Accessibility is the usability of a product, a service, an environment or a building for people with the greatest variation of skills".

The following principles are taken from a draft revision of the Guidelines for Software Accessibility (ISO, 2003):

  • Equality
    All users have equal rights and can use all of the application features.
  • Flexibility
    The application takes account of a wide range of user abilities and needs.
  • Discernability
    The application provides information to the user in a manner that is discernible for him/her.
  • Understandability
    The application provides information to the user in a manner that he/she can understand.
  • Usability
    The operator controls of the application can be operated by all users, taking account of a wide range of user skills.
  • Fault tolerance
    The application prevents as far as possible risks and adverse consequences of unintended user actions.
  • Robust technologies
    The application uses robust and standardized technologies, for maximum interoperability with tools and auxiliary programs used by the user.


4.0.Usability      4.2.Accessibility      4.3.1.Specific implementation measures

4.3.1.Specific implementation measures

  • Colors: Color should not be relied on as the only distinguishing criterion (example: red/green color blindness). Corresponding information should always be provided in the form of text information.
  • Images should always provide the ALT attribute.
  • Operator controls should be accessible not only exclusively via mouse, but also via the keyboard (for example, via the tab key for controlling form elements).
  • For videos, transcripts or video subtitles should be provided.
  • Sites should offer the opportunity of navigating to the page with keyboard input only ("Skip Navigation").
  • Colors: Ensure that there is a sufficient contrast ratio for all fonts and controls.
  • For animations, an image sequence that is too fast should be avoided. Always offer the option to pause or disable the motion sequence.