ISTA 2016. Season 4 of soft performance. This talk is a walk through some of the laws and principles of usability and human-computer interactrion: Occam’s razor, Conway's law, Jakob's law, Moore's law, Wirth's law, Hick's law, Miller’s law, Zipf’s law, Don’t make me think, and Norman's law.

1. Soft Performance
laws and principles

2. #ISTACon2016
@dsimov

3. who’s talking? Dimiter Simov (Jimmy)
usability practitioner,
UX mentor and trainer
founder of the 1st BG usability
consultancy
likes to raise usability awareness
believes that IT can be usable
product experience for SAP
HANA Cloud Platform @ SAP

4. goal
challenge your common sense

5. 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
Source: Google define

6. recall ISTA 2013: performance has a soft side
text and formatting
Fitts’ law
layout and structure
user success & engagement
presentation of progress
aesthetics 1 : 1.618 = the golden ratio

7. recall ISTA 2014: about messages
avoid messages, especially
modal ones
if you have to give a message,
make sure it is obvious:
be practical
DON’TWRITE MESSAGES,
DESIGN INTERACTIONS
1. who shows it
2. what happened
3. why
4. what users can do about it

8. recall ISTA 2015: metrics
effectiveness
efficiency
satisfaction
success rate
time on task & effort
orientation & error rate
task-level: easy or hard
overall: System Usability Scale

9. ISTA 2016: laws and
principles

10. Occam’s razor
Among competing hypotheses, the one with
the fewest assumptions should be selected.

11. About
14th century
William of Ockham
English Franciscan friar, scholastic philosopher and theologian
also: lex parsimoniae = law of parsimony
Occam’s razor
https://en.wikipedia.org/wiki/Occam%27s_razor

12. Occam’s razor
image: https://www.dropbox.com/s/1katl4icsmafzw8/Org%20To%20Customer%20Centric%20EuroIA%202016%20Gerry%20McGovern.pdf
spring 2014
success 94%
summer 2015
success 53%
Spring 2016
success 100%

13. how to boost soft performance?
go for solutions that:
require less efforts from users
offer fewer and simpler interactions
Occam’s razor

14. Conway's law
Organizations which design systems ... are
constrained to produce designs which are
copies of the communication structures of
these organizations.

15. about
1967-8
Melvin Edward Conway
computer scientist, programmer, and hacker
organizational self-centeredness
Conway's law
https://en.wikipedia.org/wiki/Conway%27s_law

16. Conway’s Law
how does this company organize its clients
image: https://online.bulbank.bg/page/default.aspx?xml_id=/bg-BG/.loginAll

17. how to boost soft performance?
study how your users think about the subject; match their mental
models
multidisciplinary teams; external eyes
Conway’s law

18. Jakob's law
Users spend most of their time on other sites.

19. about
2000
Jakob Nielsen
Jakob's law of the Internet user experience
users prefer things they are already familiar with - intuitive
Jakob's law
https://www.nngroup.com/articles/end-of-web-design/

20. can you use the web without clicking
Jakob's law
Image: http://www.dontclick.it/

21. Jakob's law
how do you request green light?

22. Jakob's law
save as

23. how to boost soft performance?
make your product work the same way as the other products out
there
stick to conventions
Jakob's law

24. Moore's law
The number of transistors in a dense
integrated circuit doubles approximately
every two years.

25. about
1965
Gordon Moore | founder of Fairchild Semiconductor and Intel
bigger hard drives, faster connections, cheaper IT equipment, more
pixels in digital cameras, bigger bandwidth, …
Moore’s law
https://en.wikipedia.org/wiki/Moore%27s_law

26. Moore’s law
the speed of Google search
https://www.youtube.com/watch?v=JO_iRBEgnLc

27. Wirth's law
Software is getting slower more rapidly than
hardware becomes faster.

28. about
1995
NiklausWirth | Swiss computer scientist, designer of Pascal, 1984
winner of theTuring Award
successive generations of computer software increase in size and
complexity, thereby offsetting the performance gains predicted by
Moore's law
software bloat
Wirth’s law
https://en.wikipedia.org/wiki/Wirth%27s_law

29. Wirth's law
the speed of Microsoft Office
Office 2007 performed slower on a typical year-2007 computer as
compared to Office 2000 on a year-2000 computer
https://goo.gl/B9Sooa

30. how to boost soft performance?
do not jump hastily on the “latest and greatest” technological miracle
stick to user goals and needs
measure efficiency and effectiveness
Moore’s and Wirth's laws

31. pick the one that you like most
parrot
cat
iguana
rabbit
swim
walk
climb
run
jump
dance
row
ride

32. Hick's law
The time it takes to make a decision increases
logarithmically with the number of possible
choices.

33. about
1950s
William Edmund Hick | British experimental psychologist and
ergonomist
Ray Hyman | American psychologist, critic of parapsychology, founder
of the modern skeptical movement
Hick–Hyman law
Hick’s law
https://en.wikipedia.org/wiki/Hick%27s_law

34. buy or subscribe
Hick's law
Image: http://www.axure.com/buy

35. cancer registry of Norway before and after
Hick's law
image: https://www.dropbox.com/s/1katl4icsmafzw8/Org%20To%20Customer%20Centric%20EuroIA%202016%20Gerry%20McGovern.pdf

36. The Paradox of Choice -Why More Is Less
Hick's law
Image: https://en.wikipedia.org/wiki/The_Paradox_of_Choice#/media/File:Paradox_of_Choice_cover.jpg

37. how to boost soft performance?
know user goals and needs – perform tasks analysis
be careful with the number of options
reduce and hide
step-by-step guidance
Hick's law

38. Miller’s law
The number of objects an average person can
hold in working memory is about seven.

39. about
1956
George Miller | a founder of cognitive psychology, psycholinguistics
and cognitive science
The Magical Number Seven, Plus or MinusTwo
human memory has limited capacity: a couple of bits
Miller’s law
https://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two

40. read this
359998234559
(359) 998 234 559
dimitersimeonovsimovjimmy
Dimiter Simeonov Simov Jimmy
Miller's law

41. how to boost soft performance?
do not make users remember or recall things you can easily show
them
chunks & delimiters
no, it is not necessary to limit menu choices, items on the home page,
categories, radio buttons, and so on to 7+/- 2
Miller's law

42. Zipf’s law
In a corpus of natural language, the frequency of
any word is inversely proportional to its rank in
the frequency table. The most frequent word
occurs twice as often as the second most
frequent one, three times as often as the third
most frequent word…

43. about
1935
George KingsleyZipf | American linguist and philologist with interests
in statistics
zipfian distribution applies to other areas: salaries, population of
cities, website popularity, pages visited, user tasks
long tail / long neck
Zipf’s law
https://en.wikipedia.org/wiki/Zipf%27s_law

44. page visits on SAP HCP documentation
Zipf’s law

45. how to boost soft performance?
know your users’ tasks
Zipf's law

46. Don’t make me think
a good software program or web site should
let users accomplish their intended tasks as
easily and directly as possible

47. about
2000
Steve Krug | an information architect and user experience professional
invisible tool
Don’t make me think
https://en.wikipedia.org/wiki/Don%27t_Make_Me_Think

48. how to boost soft performance?
make your software such that users think about how to accomplish
the task at hand not about how to use the tool
Don’t make me think

49. Norman’s law
A project is behind schedule and over its
budget the day it is started.

50. about
2010
Donald Norman | designer, psychologist, engineer
no need to start with design research – do then think
pre-existing knowledge, inhibited creativity
Norman’s law
http://www.jnd.org/dn.mss/act_first_do_the_re.html

51. how to boost soft performance?
sketch and try first
then analyze
then iterate
work with domain experts
Norman’s law

52. recall ISTA 2016: laws and principles
Occam’s razor
Conway's law
Jakob's law
Moore's law
Wirth's law
Hick's law
Miller’s law
Zipf’s law
Don’t make me think
Norman's law
go for the simplest
organizational self-centeredness
people spend more time with other designs
hardware capacity doubles every year or so
software bloats faster than hardware grows
many choices, hard and slow decisions
our memory has limited capacity
frequency is inversely proportional to rank
invisible products
a project is late and over budget on day 1

53. t
h
a
t
’
s
f
o
l
k
s
@dsimov
about.me/dsi
mov
a
l
l