Principles of User Interface Design

1. Interfaces exist to enable interaction

   Interfaces do a job and their effectiveness can be measured. The best interfaces inspire and intensify our relationship with the world.
   

2. Clarity is job #1

   People must recognise what an interface is, understand what it does, and predict what will happen when they use it. No room for confusion.
   

3. Conserve attention at all costs

   Attention is precious. Don’t litter applications with distractions. When use is the primary goal, attention becomes the prerequisite.
   

4. Keep users in control

   Surface system status, describe causation, and give insight into what to expect at every turn. Don’t worry about stating the obvious.
   

5. Direct manipulation is best

   Design interfaces with minimal footprint, recognising natural human gestures. Users should feel they’re directly manipulating their focus, not UI elements.
   

6. One primary action per screen

   Every screen should support a single action of real value. Screens with multiple primary actions become confusing quickly.
   

7. Keep secondary actions secondary

   Make secondary actions lighter weight visually or show them after the primary action is achieved.
   

8. Provide a natural next step

   Anticipate what the next interaction should be and design to support it. Don’t leave people hanging after they complete an action.
   

9. Appearance follows behavior

   Elements should look like how they behave. People should predict how something works just by looking at it. Form follows function.
   

10. Consistency matters

    Elements that behave the same should look the same. Unlike elements should appear different. Don’t obscure important differences for consistency’s sake.
    

11. Strong visual hierarchies work best

    Users should view elements in the same order every time. Visual weight is relative: when everything is bold, nothing is bold.
    

12. Smart organisation reduces cognitive load

    Smart organisation makes the many appear as the few. Show relationships through placement and grouping so users don’t have to figure them out.
    

13. Highlight, don't determine, with colour

    Colour should guide attention and highlight, but not be the only differentiator. Use muted backgrounds for extended reading, saving bright hues for accents.
    

14. Progressive disclosure

    Show only what’s necessary on each screen. Defer decisions to subsequent screens by progressively disclosing information as needed.
    

15. Help people inline

    Provide help inline and contextually, available only when and where needed. Don’t make people hunt for answers in help documentation.
    

16. A crucial moment: the zero state

    Design for the first-time experience when nothing has occurred yet. Provide direction and guidance, not a blank canvas.
    

17. Great design is invisible

    Successful design goes unnoticed because users focus on their goals, not the interface. Happy users are often silent.
    

18. Build on other design disciplines

    Visual design, typography, copywriting, information architecture—all are part of interface design. Pull insights from unrelated disciplines too.
    

19. Interfaces exist to be used

    Design succeeds when people use what you’ve created. It’s about creating an environment for use, not satisfying the designer’s ego.
    

Tags: Universal, People