Essential UI Design Principles and Standards

Smith & Mosier Design Categories

The following categories represent the Smith & Mosier standards for interface design:

• Data Entry (199): User actions involving input of data to a computer and computer responses to such inputs.
• Data Display (298): Computer output of data to a user and assimilation of information from such outputs. Note: Data should be displayed in a usable form; do not force users to convert displayed data.
• Sequence Control (184): User actions and computer logic that initiate, interrupt, or terminate transactions.
• User Guidance (110): Error messages, alarms, prompts, labels, and formal instructional material to assist user interaction.
• Data Transmission (83): Computer-mediated communication among system users and other systems.
• Data Protection (70): Security measures to protect data from unauthorized access, destructive user actions, and system failure.

Applicability to Modern Interfaces

While Smith & Mosier (1986) guidelines were initially developed for text-based UIs, they remain highly applicable to modern Graphical User Interfaces (GUIs).

Lewis and Rieman Design Principles

• The Clustering Principle: Organize the screen into visually separate blocks of similar controls, preferably with a title for each block.
• The Visibility Reflects Usefulness Principle: Make frequently used controls obvious and accessible; hide or shrink controls used less often.
• The Intelligent Consistency Principle: Use similar screens for similar functions (e.g., consistent placement of help buttons).
• The Color as a Supplement Principle: Do not rely solely on color to carry information; use it sparingly to emphasize data.
• The Reduced Clutter Principle: Maintain a clean interface by using consistent styles and sizes across all menus.

Shneiderman's 8 Golden Rules

1. Strive for consistency: Consistent sequences of actions should be required in similar situations.
2. Enable frequent users to use shortcuts: Utilize abbreviations and function keys.
3. Offer informative feedback: Provide feedback for every operator action.
4. Design dialog to yield closure: Organize sequences of actions into groups with a clear beginning, middle, and end.
5. Offer simple error handling: The system should detect errors and provide simple mechanisms for resolution.
6. Permit easy reversal of actions: Ensure users know that errors can be undone.
7. Support internal locus of control: Design the system to make users the initiators of actions.
8. Reduce short-term memory load: Keep displays simple and intuitive.