When thinking about performance we should definitely take objective metrics and strive to make our systems faster, more reliable, and more robust. We should also pay attention to the soft side of performance – the user perception – as how users perceive the performance of a system is the ultimate measure of the real performance of that system and thus a significant factor for the success of the system. Presented at ISTA 2013 http://istabg.org/soft-performance-2/, UXify 2014 http://uxify.org/uxify-conf/schedule#tracktwo

1. Soft Performance
Dimiter Simov, SAP

2. performance
a task or operation seen in terms of how successfully it
is performed
“pay increases are now being linked more closely to
performance”
the capabilities of a machine, product, or vehicle
“the hardware is put through tests which assess the
performance of the processor”
2Source: Google define

3. Goals
Show that bytes and seconds are not the only way to think
about performance
Give some pieces of advice on how to optimize software for
soft performance
3

4. Seconds are important
4
The time visitors
were willing to wait for
a page to load
before they left
Source: Slow websites can cost you money!

5. 3 seconds load time is old news
in 2012, 400 milliseconds was too long
what about today?
5Source: For Impatient Web Users, an Eye Blink Is Just Too Long to Wait

6. Read this text please
Performance is an objective hard measure of speed, reliability, robustness, endurance, and more. Performance however
has also a soft side – the user perception. Today we will discuss soft performance in some detail – the idea is to give you
an idea. Some of the things that affect soft performance are the way we format texts, what messages we provide and
how, obeying or not with the law of Fitts, ordering the interface in a specific layout, the way of structuring content,
users’ ability to complete their tasks, keeping users engaged, presenting progress in ways that users perceive faster, and
providing aesthetically pleasing interfaces.
6

7. Now try this one
Performance:
 objective measure of speed, reliability, robustness, endurance…
 has a soft side – user perception. We discuss it today.
Things that affect soft performance:
user success
user engagement
presentation of progress
aesthetics
texts and formatting
messaging
Fitts’s law
structure and layout
7

8. What issues do you see with text 1
Performance is an objective hard measure of speed, reliability, robustness, endurance, and more.
Performance however has also a soft side – the user perception. Today we will discuss soft performance
in some detail – the idea is to give you an idea. Some of the things that affect soft performance are the
way we format texts, what messages we provide and how, obeying or not with the law of Fitts, ordering
the interface in a specific layout, the way of structuring content, users’ ability to complete their tasks,
keeping users engaged, presenting progress in ways that users perceive faster, and providing
aesthetically pleasing interfaces.
Italics
Low contrast
Small font size
Justified alignment
No highlighting of keywords
Block of text
Wordiness
8

9. Formatting dates and numbers
2013-03-12 12:30:45
12 Mar 2009 12:30:45
5 years ago 12 Mar 2009
9

10. TEXT AND FORMATTING
Texts that are written and formatted well
are faster and easier
to scan, read, understand, and remember
compared to non-formatted texts
10

11. Example
Résumé of the homepage of a website about Nebraska
Goal of the site: attract tourists
Source: http://www.nngroup.com/articles/how-users-read-on-the-web/11

12. Original text
Nebraska is filled with internationally recognized attractions that
draw large crowds of people every year, without fail. In 1996, some
of the most popular places were Fort Robinson State Park (355,000
visitors), Scotts Bluff National Monument (132,166), Arbor Lodge
State Historical Park & Museum (100,000), Carhenge (86,598), Stuhr
Museum of the Prairie Pioneer (60,002), and Buffalo Bill Ranch State
Historical Park (28,446).
12

13. In half: 58% better readability
In 1996, six of the best-attended attractions in Nebraska were Fort
Robinson State Park, Scotts Bluff National Monument, Arbor Lodge
State Historical Park & Museum, Carhenge, Stuhr Museum of the
Prairie Pioneer, and Buffalo Bill Ranch State Historical Park.
13

14. Scannable: 47% better readability
Nebraska is filled with internationally recognized attractions that
draw large crowds of people every year, without fail. In 1996, some
of the most popular places were:
 Fort Robinson State Park (355,000 visitors)
 Scotts Bluff National Monument (132,166)
 Arbor Lodge State Historical Park & Museum (100,000)
 Carhenge (86,598)
 Stuhr Museum of the Prairie Pioneer (60,002)
 Buffalo Bill Ranch State Historical Park (28,446).
14

15. Objective: 27% better readability
Nebraska has several attractions. In 1996, some of the most-visited
places were Fort Robinson State Park (355,000 visitors), Scotts Bluff
National Monument (132,166), Arbor Lodge State Historical Park &
Museum (100,000), Carhenge (86,598), Stuhr Museum of the Prairie
Pioneer (60,002), and Buffalo Bill Ranch State Historical Park (28,446).
15

16. Combined: 124% better readability
In 1996, six of the most-visited places in Nebraska were:
 Fort Robinson State Park
 Scotts Bluff National Monument
 Arbor Lodge State Historical Park & Museum
 Carhenge
 Stuhr Museum of the Prairie Pioneer
 Buffalo Bill Ranch State Historical Park
16

17. piece
of
advice Write and format well
Training in writing and formatting
Large fonts
Important info at the top
Highlighted important concepts
Less is more
17

18. Check this out
What can a user who reads the following message do?
18

19. It should not be hard to parse the input and ignore spaces,
dashes, dots…
Validation

20. Necessary or not?
20

21. piece
of
advice Think about messaging
Try to avoid messages
 don’t write messages, design interactions
If you have to give a message, make sure it says:
 what happened
 why
 what users can do about it
21

22. Which is faster to click
the mouse is here
22

23. Quiz
Which point on the screen is the fastest to click?
Which are the other four?
Why?
23

24. Fitts’ Law
The time needed to reach a target depends on the distance
to and size of the target
24







W
D
baT
2
1log2

25. Quiz
Which one is better?
You can click here to see Jimmy’s presentation slides
View Jimmy’s presentation slides
25

26. X
~7X

27. FITTS’ LAW
Objects that are larger and closer
are easier and faster to point and
click/touch
compared to objects that are small and far
away
27

28. piece
of
advice Fitts’ law is a friend of yours
Large clickable things: links, buttons
Action buttons close to where the interaction is
Objects stuck to the edges of the screen
Take Tog’s quiz: http://www.asktog.com/columns/022DesignedToGiveFitts.html
28

29. Quiz
Which country used to have the largest internet
population?
Why?
wrong default
collecting unnecessary info
29

32. STRUCTURE & LAYOUT
User interfaces
that are light and make sense to users
are faster and easier to use
they are less error-prone as well
32

34. 1 user per 1 hour
Annual non-productive time: ~ 33 work days
Action
Times per 1
hour Duration
Loss per 1
hour
Loss per 1
month
Reload 3 34 sec 2 min 4 hours
Switch tabs 63 4 sec 4 min 10 hours
Resize 8 17 sec 2 min 5 hours
Total 8 min 19 hours
34

36. piece
of
advice Match user tasks and talk
Recognition, not recall
Match user tasks and workflows
Least time on page
Meaningful defaults
Hidden non-important elements
36

37. The faster website
10 websites
Users performed their own personal tasks
No two users performed the same tasks on any site
For each site, users rated how fast they felt the site was -
perceived speed
Actual speed measured as well
Source: The Truth About Download Time, http://www.uie.com/articles/download_time/37

38. Which site was faster?
about.com
actual speed: 8 seconds
perceived speed: slowest
amazon.com
actual speed: 36 seconds
perceived speed: fastest
38

39. Surprise!
Correlation between perceived speed and success
Even when a site is slow, if users succeed, they feel it fast
No correlation between actual speed and success
Even when a site is fast, if users fail, they feel it slow
39

40. USER SUCCESS
Users who successfully perform their tasks
with an UI are likely to perceive it as
performing well
40

41. piece
of
advice Make sure users succeed
When users complain that your service is slow, check how
often they can accomplish their tasks before you decide to
optimize download speeds and server response times
41

43. USER ENGAGEMENT
Keeping users engaged reduces subjective time
43

44. Quiz
How do you speed up
a slow elevator?
Install mirrors
See The Evolution of a Legend,
http://www3.sympatico.ca/karasik/GF_evolution_of_legend.html
44

45. Do elevators nowadays
really need mirrors?
Why?
45

46. Quiz
Why is streaming video successful?
We start watching instantaneously
46

47. piece
of
advice Keep users engaged
Do not interrupt user flow
Give users something to do while waiting: watch, read, click
47

48. 48
Watch this

49. GO

50. GO

51. GO

52. Quiz
Which of the previous three slides was the fastest?
Why?
52

53. Why
…humans perceive time in non-linear way
…people perceive as fastest a progress bar that starts slow
and accelerates towards the end
Source: http://www.chrisharrison.net/index.php/Research/ProgressBars53

54. piece
of
advice Indicate progress
Speed up your progress indicators
54

55. Which shape do you prefer?
Why?
3
6
2.79
7.13
55

56. Geometric and natural proportions
Vlad Golovach claims that we perceive objects that have
geometric or natural proportions as harmonic and
aesthetically pleasing
Source:http://www.ncbi.nlm.nih.gov/pubmed/19787509
Natural
1 x 1.618 – the golden ratio
1 x 3.14 – π
1 x 414 – square root of 2
Geometric
1 x 1
1 x 2
1 x 3
2 x 3
56

58. AESTHETICS
Aesthetically pleasing interfaces improve
performance and usability
58

59. Visual aesthetics affects performance
Four versions of a website
 high and low visual aesthetics
 good and poor usability
Beauty compensated for poor usability by speeding up task
completion
Source:http://www.ncbi.nlm.nih.gov/pubmed/1978750959

60. piece
of
advice Tend to appearance
Visual designer
Proportions
Beauty
60

61. Performance has a soft side
text and formatting
messaging
Fitts’ law
layout and structure
user success and engagement
presentation of progress
aesthetics 1 x 1.618 – the golden ratio 61

62. you will find out other factors
… let me know
Questions?