1. Human Interface Guidelines
Networking Lab
Lee Ho Jae

2. Introduction Principles to create excellent software
Good human interface with design and processes

3. Design Process – Involving Users
Know your Audience
- Define, understand, similar product, design for customers
Analyze User Tasks
- Define & analyze, conceptual model, overall workflow
Build Prototypes
- Prototype to test and verify design
- Storyboard, prototyping software, writing code

4. Design Process – Involving Users
Observe Users
- Try out prototype and observe reactions
- Verify test scope and instructions
- Supplement prototype with results
Guidelines for Observing Users
- Describe test purpose, duration
- Test product, not the participant
- Think-aloud protocol
- Without any interference or extra help
- Use the result as it is (don’t blame users for inexperience)
- Review all results with a cross-functional team

5. Design Process – Making Design Decisions
Weigh the cost against the potential benefits
Adding a feature to application
- Larger, slower, complex, conflict each other, documentation
Avoid feature cascade
- Appropriate feature to original intent and main workflow
Apply the 80 Percent Solution
- Meet the needs of at least 80 percent of users

6. Characteristics of Great Software
High Performance
- Frequently measure using metrics(not assumptions)
- Modern APIs, threads, memory management system
- Avoid polling, unnecessary I/O, loading resource before use
Ease of Use
- Metaphors, feature with real benefit
- Intelligent default settings
- Present information step by step
- Useful error messages, undo, redo
- Internationalize and assistive to disabilities

7. Characteristics of Great Software
Attractive Appearance
- Use high-quality graphics and icons, 32-bit color
- Use system-provide interface builder
- Use modern APIs
Reliability
- Earn user’s trust (integrity of user’s data)
- A predictable user interface (same action, same result)
- Validate user input (data type, length, …)
- Test software under various conditions
- Use modern APIs, standard-based APIs

8. Characteristics of Great Software
Adaptability
- Keep working even if the current conditions change
- If file system or network fails…?
- Changes in screen availability and resolution
Interoperability
- Communicate across environments
- Same file format, extensions on all platform
- Standard data-exchange protocol
- Save configuration data using system preferences

9. Characteristics of Great Software
Mobility
- Battery power, movability, configuration changes
- Avoid polling, minimize access on movable drive
- Be sensitive to screen resolution changes

10. Human Interface Design - Principles
Metaphor
- Convey concepts and features
- File folders storing documents, iTunes, iPhoto
Reflect the User’s Mental Model
- Experience from real-world, other software
- Familiarity, Simplicity, Availability, Discoverability
Explicit and Implied Actions
- See, Select, Perform
- Menu list, drag-and-drop operation
Direct Manipulation
- Implied Action
- Drag selected text, resizing of a graphic object

11. Human Interface Design - Principles
User Control
- User decides everything
- Help only with an appropriate warning
Feedback and Communication
- Inform users of current status of application
- MSN is going to tray. Progress indicator
Consistency
- Consistent terminology, icons
- Versions, user’s expectations
WYSIWYG
- Printing, Publish
- Features easily accessible (Don’t hide in menu)

12. Human Interface Design - Principles
Forgiveness
- Easily reversible action, warning for irreversible loss
Perceived Stability
- Use standard graphical elements
- Dimmed menu item, user-modifiable settings
Aesthetic Integrity
- High quality of icons, anti-aliased text
- Consistent scale in fonts, controls
Modelessness
- Exception : short-term mode, alert, installer

13. Human Interface Design - Principles
Managing Complexity
- Complex task, simple interface
- Progressive disclosure, separated info-window, preferences

14. Human Interface Design - Users
Worldwide Compatibility
- Cultural Values (Owl – wisdon/black magic, holiday)
- Language differences (standard usage/syntax)
- Text Display/Editing (align direction, scanner)
- Resource (region dependent data, logical flow of content)
Universal Accessibility
- Visual Disabilities (high contrast, text sizes, zooming, voice)
- Hearing Disabilities (visual cue come with audible cue)
- Physical Disabilities (Sequentially instead simultaneously)

15. Human Interface Design – Extend Interface
Build on the Existing Interface
- Push button (round shaped with a label)
Don’t Assign New Behaviors to Existing Objects
Create a New Interface Element Cautiously
- Avoid unnecessary complexity
- Apply changes to new user interface from system interface

16. Prioritizing Design Decisions
Meet Minimum Requirements
- Single menu bar, multilayered window
- Files in proper locations, Standard Controls
- Avoid system-reserved keyboard shortcuts

17. Prioritizing Design Decisions
Deliver the Feature Users Expect
- Communication (error messages, feedback on commands)
- High-quality graphics
- User assistance (Help), Drag-and-drop

18. Prioritizing Design Decisions
Differentiate Your Application
- Modelessness, fast user switching (only login)
- Internationalization of interface
- Accessibility to users with disabilities
- High Performance and reliability
- Surprise and delight (keep user’s mental model in mind)