The usability of a system is improved when its status and methods of use are clearly visible.

The more visible functions are, the more likely users will be able to know what to do next. Incontrast, when functions are “out of sight,” it makes them more difficult to find and know how to use.

— Don Norman

According to the principle of visibility, systems are more usable when they clearly indicate their status, the possible actions that can be performed, and the consequences of the actions once performed. This is based on the fact that people are better at recognizing solutions when selecting from a set of options, than recalling solutions from memory. When it comes to the design of complex systems, the principle of visibility is perhaps the most important and most violated principle of design.

Observations

Implementing this principle relays on many others such as Visual Hierarchical, Empathy, etc. and as the best practices it should also aligned with Pareto Principle. To incorporate visibility into a complex system, one must consider the number of conditions, the number of options per condition and number of outcomes.

Example: A software menu. The category names remain visible, but the controls and information remain concealed until the parent control is activated. Context sensitivity reveals and conceals controls and information based on different system contexts. Relevant controls and information for a particular context are made highly visible, and irrelevant controls (e.g., unavailable functions), are minimized or hidden.

Further Readings

• Coursera – Design Principles
• Universal Principles Design
• The Design of Everyday Things
• Introduction to Design and Development Principles
• Usability Heuristics for Bots
• Visibility: 5 Principles of Interaction Design To Supercharge Your UI