This document outlines key principles for user interface (UI) design, emphasizing the importance of aesthetic integrity, consistency, user feedback, and intuitive navigation. It highlights the need for user-centric terminology, appropriate use of color and typography, and the significance of minimizing user input effort. The guidelines also stress the necessity for adaptable designs that enhance user experiences across mobile devices, ensuring that interfaces are understandable and engaging.

1. UI Design
Ivano Malavolta
ivano.malavolta@univaq.it
http://www.di.univaq.it/malavolta

2. Some apps are just so
shiny you want to lick them
[cit.]

3. Roadmap
• Intro + Examples
• Human Interface Principles
• Platform Characteristics
• UX Guidelines

4. Introduction
Before focussing on UI….
in mobile you can always control
Content Visual
naming Design

5. Content Naming
Before you start reasoning on the UI…
Define an APP DICTIONARY
Write down the terms and messages used in
the app
Ex.
– tweets in Twitter
– Likes in Facebook

6. Visual Design
The direct representation of everything under
your app
The first impression the user will have
It is not only about layout & colors…
it is about SENSORY SENSATIONS

7. Example 1
http://drbl.in/czjd

8. Anti-example 1

9. Roadmap
• Intro + Examples
• Human Interface Principles
• Platform Characteristics
• UX Guidelines

10. Aesthetic Integrity
It’s a measure of how well the appearance of
the app integrates with its function
• Productive app order & clarity
• Game gamish, frivoulous
• …

11. Consistency
Take advantage of the standards and paradigms
people are comfortable with
Does it use system-provided controls, views, and icons correctly
correctly?
Is the application consistent within itself
itself?
Does text use uniform terminology and style
style?
Can people predict what will happen?

12. Direct Manipulation
Try to let your users direct manipulate objects
in your app
Users can experience direct manipulation when they:
• Rotate or otherwise move the device
to affect onscreen objects
• Use gestures to manipulate
onscreen objects
• Can see that their actions have
immediate, visible results

13. Feedback
Acknowledge people’s actions and assures them
that processing is occurring
Users expect
• immediate feedback
• status updates during
lengthy operations

14. Metaphors
Use metaphors for objects in the real world in
your app
Users will quickly grasp how to use the app
Ex.
– folders
– photo sliders
–…

15. User Control
People, not apps, should initiate and control
actions
Apps can suggest actions, but users must do them
Apps can only infer data from the context
Users expect to be able to stop an operation that’s
underway

16. Example 2
http://www.perspecdev.com/Faster/

17. Anti-example 2

18. Roadmap
• Intro + Examples
• Human Interface Principles
• Platform Characteristics
• UX Guidelines

19. Display is Paramount
The DISPLAY is (usually) the only means that users use
to interact with your app!
• The comfortable minimum size of tappable UI
elements is 44 x 44 points
• The quality of app artwork is fundamental
• The user’s focus is on the content

20. Display Orientation
Users can rotate the device at any time and for
any reason
users tend to expect apps to launch in the
device orientation they’re currently using
TIP.
TIP You can use the splashscreen image to let the user rotate
the device

21. Gestures
Users don’t click, they use gestures
– tap/double tap
– drag
– zoom/pinch
– swipe
– flick
Users expect all these gestures to work the same,
same
regardless of the app they’re currently running

22. One App at a Time
(at the moment) One app is visible in the foreground
at a time
When people switch from one app to another, the
previous app goes in background and its user
interface goes away
Some applications might need to continue running in
the background

23. User Help
Keep onscreen user help as minimal as possible
In general, users don’t need onscreen help
content to tell them how to use the device or
the apps
Remember of the Consistency human-interface
principle

24. Example 3
http://kangarooband.it/

25. Anti-example 3

26. Roadmap
• Intro + Examples
• Human Interface Principles
• Platform Characteristics
• UX Guidelines

27. Layout
It should be defined the first aspect to fix
you need pure feedback on it
lo-fi wireframing
Tablets
content scrolled
horizontally
http://bit.ly/GTp82Q

28. Colors psychology
Users react to different colors differently
Colors evoke emotions
BLU
productiveness, interiors,
skies, peace, unity, harmony,
tranquility, calmness, trust,
coolness, confidence,
conservatism, water, ice,
loyalty, dependability,
cleanliness, technology…
http://mobiledesign.org/color

29. Color Palette
Predefined number of colors to use consistently in
your app
You can use tools like
palette choosers, or
palette pickers from images
OR
You can define your palette manually through the
color wheel
http://kuler.adobe.com

30. Color Wheel
Complementary
when you want
something to stand out
Analogous
choose one color to
dominate, a second to support,
the third color is as an accent
http://bit.ly/GTv7on

31. Color Wheel
Triad
let one color dominate
and use the two others
for accent
Square
works best if you let
one color be dominant
http://bit.ly/GTv7on

32. Typography
It is about:
• selection of the correct font
• understanding sizes
• applying conventional design methodologies
(size, shape, contrast, color, position, space, etc.)
http://bit.ly/GTvuzj

33. Readability guidelines
1. Use a high-contrast typeface
high-
– Devices are usually used outside
2. Use the right typeface (font)
http://bit.ly/GTwUtv

34. Readability guidelines
3. Provide decent leading
– Leading = the space between two lines
4. Leave space on the right and left of each line
5. don’t crowd the screen

35. Readability guidelines
6. Generously utilize headings
– Divide the content into paragraphs
7. Use short paragraphs
– 2-3 sentences at most

36. Respect User-Entered data
Input is hard,
Users slip (and sleep!)
Do whatever it takes to
preserve user data
and plan for real-world behaviors

37. Realize That Mobiles Are Personal
one device for one person
Don’t continuously ask for name, data, etc.
Only implement passwords and clear personal
information when required

38. Ensure That Lives Take Precedence
Don’t interrupt people’s life!
Differently from desktops
Mobiles are glanced at, used in gaps between
conversation and driving and watching TV

39. Use Your Sensors
Whenever possible, perform actions for the
user based on sensors and user data
Ex.
Why should you have to silence your phone for a meeting, when
the phone knows where you physically are and knows from your
calendar that you have a meeting in that room right now?

40. Focus on the Primary Task
you need to determine what’s most important in
each context or screen and…
exclusively!
focus on it exclusively!
Your app definition statement will help you
focus your app on its primary task

41. Elevate the Content that People Care
About
Give your users what they need most!
most!
For example, in a game, people care about the experience,
they don’t expect to manage, consume, or create content
• Minimize the number of controls in the UI
• Customize controls so that they integrate with your
app’s graphical style
• Fade controls away after people have stopped
interacting with them for a little while

42. Think Top Down
Put the most frequently used information
near the top
Because users hold the device in the following ways:
• In the left hand and gesturing with a
finger of the right hand
• In one hand and gesturing with the
hand,
thumb of the same hand
• Between their hands and gesturing
hands,
with both thumbs

43. Logical Path
Make the path through the information you
present logical and easy to predict
– put markers to let them where they are
– put a back-button
Give users only one path to a screen

44. Easy Usage
Your app must be instantly understandable by users
you cannot assume they want or they have time to learn
how to use your app
Make the main function of your app
immediately evident

45. User-Centric Terminology
use terminology your users understand
avoid technical jargon
– This does not hold if your target user is a technical guy

46. Minimize the Effort Required for User
Input
Inputting information takes time and attention,
minimize it
TIP.
TIP If your app asks users a lot of input data, you have to
revise your design!
Balance any request for input by users with what
you offer them in return
Get information from the OS when appropriate
OS,
– for example: contacts, address, events in the calendar…

47. Enable Collaboration
Push for collaboration and sharing with others
When appropriate, make it easy for users to
interact with others
– allow them to share things like their location,
opinions, and high scores
For tablets think of ways to allow more than one
tablets:
person to use your app on the same device

48. Brand Appropriately
Incorporate a brand’s colors or images in a refined,
unobtrusive way
Avoid taking space away from the content people care
about
– Alternative: subtly customize the background of a screen

49. Make Search Quick
In apps with a lot of data, SEARCH can be a
primary function
Build indexes of your data so that you are always prepared
for search
Live-
Live-filter local data so that you can display results
more quickly
Display a search bar above a list or the index in a list
Display placeholder content right away and partial
results as they become available

50. Be Succinct
Think like a newspaper editor, and strive to convey
information in a condensed, headline style
When your UI text is short and direct users can
direct,
absorb it quickly and easily
Give controls short labels, or use well-understood
labels well-
symbols
users should tell what they do at a glance

51. Use UI Elements Consistently
Follow the recommended usages for standard user
interface elements
you can build on users’ prior experience
Avoid radically changing the appearance of a control
that performs a standard action
Never use the standard buttons and icons to mean
something else

52. Make Targets Fingertip-Size
Display may change, but the average size of a
fingertip does not!
Give tappable elements in your application a
target area of about 44 x 44 points
If you create smaller controls, the app becomes much less
enjoyable
or people may focus on the interface only, rather than
the content

53. Ask People to Save Only When
Necessary
People should have confidence that their work is
always preserved unless they explicitly cancel or
delete it
Never ask for saving data it should be done
data,
automatically
– You can ask to either edit or delete data

54. Make Modal Tasks Occasional
Modality prevents users’ freedom by interrupting
their workflow and forcing them to choose a
particular path
Keep modal tasks fairly short and narrowly
focused
Always provide an obvious and safe way to exit a
modal task

55. Start Instantly
Avoid displaying an About window or a splash screen
Avoid asking people to supply setup information
Delay a login requirement for long as possible:
– Focus your solution on the needs of 80 percent of your
users
– Get as much information as possible from other sources
– If you must ask for setup information, put it in your app’s
settings

56. Always Be Prepared to Stop
Save user data as often as reasonable
Save the current state when stopping

57. Example 4
http://instagr.am/

58. Anti-example 4

59. A Final BAD example
Layout & icons
http://www.androiduipatterns.com/2011/11/
cautionary-example-of-bad-design.html

60. A Final BAD example
Navigation buttons
http://www.androiduipatterns.com/2011/11/
cautionary-example-of-bad-design.html

61. A Final BAD example
Error Handling
http://www.androiduipatterns.com/2011/11/
cautionary-example-of-bad-design.html

62. A Final BAD example
Data Handling
http://www.androiduipatterns.com/2011/11/
cautionary-example-of-bad-design.html

63. And maybe a good one…
…developed in one single night…
http://www.musicatch.info

64. References
Chapter 8
http://bit.ly/H4GnKZ
http://bit.ly/H4Gqq5

65. BRAINSTORMING