UI/UX Design
User Interface and User Experience design — principles, research methods, and interaction patterns.
Core Principles
Gestalt Principles
Gestalt describes how the human brain perceives visual elements as groups:
| Principle | Meaning |
|---|---|
| Proximity | Elements close together appear related |
| Similarity | Similar elements appear to belong together |
| Continuity | The eye follows paths, lines, and curves |
| Closure | The brain fills gaps to perceive complete shapes |
| Figure/Ground | Objects are perceived against a background |
Fitts’s Law
The time to reach a target is a function of its size and distance. Implication: interactive elements (buttons, links) should be large enough and close enough to where users are.
Nielsen’s 10 Usability Heuristics
- Visibility of system status
- Match between system and real world
- User control and freedom
- Consistency and standards
- Error prevention
- Recognition rather than recall
- Flexibility and efficiency of use
- Aesthetic and minimalist design
- Help users recognize, diagnose, and recover from errors
- Help and documentation
UX Research Methods
| Method | When to Use |
|---|---|
| User interviews | Discover motivations, mental models |
| Usability testing | Evaluate specific tasks and flows |
| Card sorting | Understand information architecture |
| A/B testing | Compare two design variants with real users |
| Heuristic evaluation | Expert review against usability principles |
References
- Nielsen, J. Usability Engineering. Morgan Kaufmann, 1994.
- Norman, D. The Design of Everyday Things. Revised ed., Basic Books, 2013.
- Nielsen Norman Group. 10 Usability Heuristics. https://www.nngroup.com/articles/ten-usability-heuristics/
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