Principles of Accessible eLearning Content


Typical digital, interactive systems require the user to engage on four fundamental levels.  In the area of accessible web design, these principles are known as POUR: perceivability, operability, understandability, and robustness. 

Although the POUR principles originated to describe accessible web design, they are applicable in a variety of contexts.  Designers and developers can apply these principles to their development tools and practices to achieve a greater degree of accessibility and usability throughout their systems.

Perceivable Content

Perceivable content may be accessed by the user via the senses, including sight, sound, or touch.  In any form or format, users must be able to perceive the content regardless of blindness, visual acuity, color-blindness, deafness, or other sensory condition. This includes the presence and purpose of interactive elements and controls.

Operable Content

Operable content refers mainly to interactive controls like links, buttons, tabs, sliders, and other widgets.  Users must be able to interact with interactive elements regardless of their input method (e.g., mouse, keyboard, voice command).  This includes focusing onto objects with the keyboard, using keystrokes to change or set values in a control, navigating complex menus and processes, and activating objects via keystrokes.

Understandable Content

Understandable systems are easy for a user to learn; use; and remember.  This includes the use of language indicators; explanations of acronyms and abbreviations; predictable and standardized navigation; consistent naming, placement, and formatting of recurring elements; alerting the user to changes of context, including live alerts and updates; and other techniques. 

Robust Content

Robust systems adhere to standards and guidelines that permit them to be used across the widest possible spectrum of technologies.  Systems that don't adhere to such guidelines may be unusable by common user technologies, including assistive technologies.