The document discusses what makes software usable for end users. It defines usability according to ISO standards as the extent to which users can achieve goals effectively, efficiently and satisfactorily within a specified context of use. The definition emphasizes considering the user, product, goals and context of use when evaluating usability. Good design decisions require understanding the users, their skills, goals and how the product fits within their workflow and environment.

1. What
makes
an
applica/on
a
“good”
applica/on
?
How
is
so'ware
experienced
by
end-­‐users
?
Chris7an
Campo
EclipseCon
2012

2. Who
are
we
?
•
Chris/an
Campo
How
is
so:ware
experienced
by
end-­‐users
?
•
What
is
Usability
?
•
Flow
?
•
“Gestalt”
Laws
?

3. So:ware
Quality
Efficiency
Func7o-­‐
Usability
So'ware
nality
Quality
Portabi-­‐ Maintain
lity
ability

4. Usability,
a
defini/on
Defini/on
of
Usability
"The
extent
to
which
a
product
can
be
used
by
specified
users
to
achieve
specified
goals
with
effec:veness,
efficiency,
and
sa:sfac:on
in
a
specified
context
of
use."
Source:
ISO
9241-­‐11

5. Usability
Defini/on
of
Usability
"The
extent
to
which
a
product
can
be
used
by
specified
users
to
achieve
specified
goals
with
effec1veness,
efficiency,
and
sa1sfac1on
in
a
specified
context
of
use."
Source:
ISO
9241-­‐11

6. Usability
Product,
User,
Goal,
and
Context
of
Use
"The
extent
to
which
a
product
can
be
used
by
specified
users
to
achieve
specified
goals…
…in
a
specified
context
of
use."
Context of Use
Input
Output
USER
PRODUCT
Output
Input
I have
Goals
Source:
Productergonomie,
H.
Dirken

7. Usability:
the
user
Input
User
• Sight,
Hearing,
Taste,
Smell,
Touch,
Balance
&
Accelera7on,
Throughput
Temperature
• Decision
(processing),
Output
Memory
(storing)
• Motor
skills,
Speech
Context of Use
Input
Output
Throughput
Throughput
PRODUCT
Output
Input
Source:
Productergonomie,
H.
Dirken

8. Usability:
the
product
Input
• Keyboard/Keypad,
Mouse,
Joys7ck,
Product
Microphone,
Touch
Screen
Output
Throughput
• Monitor,
Internal
speak,
Vibra7on
• Decision
(processing),
Memory
(storing)
Context of Use
Input
Output
Throughput
Throughput
USER
Output
Input
Source:
Productergonomie,
H.
Dirken

9. Usability:
context
of
use
Context
of
Use
Context
o
• Use
environment
(Environmental-­‐,
f
Use
Social-­‐
Technological
context
• E.g.
Temperature,
Noise,
Pressure,
Ligh7ng
Condi7ons,
Other
products
(e.g.
safety
glasses,
gloves),
Social
Context
Context of Use
Input
Output
Throughput
Throughput
USER
PRODUCT
Output
Input
Source:
Productergonomie,
H.
Dirken

10. Design
decisions
?
Product,
User,
Goal,
and
Context
of
Use
"The
extent
to
which
a
product
can
be
used
by
specified
users
to
achieve
specified
goals…
…in
a
specified
context
of
use."
Context of Use
Input
Product
Output
Throughput
Throughput
USER
Output
Input
?
Source:
Productergonomie,
H.
Dirken

11. Design
decisions:
the
user
User
• What
goals
does
the
user
•
Required
domain
knowledge
have?
knowledge
(what
does
the
user
•
Vocabulary
of
the
domain
need
to
know
to
accomplish
their
job?)
•
How
exis7ng
products
are
used
•
Abili7es
and
impairments?
• How
do
the
goals
of
my
so'ware
relate
to
other
goals
of
the
user’s
job?
•
Experience
level?

12. Design
decision:
context
of
use
Context
of
Use
•
What
are
characteris7cs
of
•
Context
of
how
the
product
the
context
(e.g.
heat,
noise)
fits
into
their
lives/workflow
•
Ar7facts
in
the
context
Library
Factory
floor
Public
space
Crowded
office
space

13. What
does
this
all
mean
?
•
To
make
a
more
usable
design,
you
need
to
know:
› Who
are
your
users
?
› What
are
their
skills
?
› What
are
their
goals
?
› In
which
context
is
your
product
used
?
•
The
informa/on
on
user,
context,
goals
will
help
you
make
realis/c
design
decisions
•
How
to
get
this
informa/on
?
› USABILITY
RESEARCH
&
TESTING!

14. Usability
Defini/on
of
Usability
"The
extent
to
which
a
product
can
be
used
by
specified
users
to
achieve
specified
goals
with
effec1veness,
efficiency,
and
sa1sfac1on
in
a
specified
context
of
use."
Source:
ISO
9241-­‐11

15. Usability:
effec/veness
•
Effec/veness
› Defini7on:
Successful
in
producing
an
intended
result
Sports
car
Bicycle
›
Measuring
Effec7veness
›
Percentage
of
task
›
Number
of
features
or
completed
commands
used
›
Ra7o
of
success
to
failure
Source:
hfp://www.usabilitymetrics.com/usability-­‐metrics.html

16. Usability:
efficiency
•
Efficiency
› Defini7on:
Achieving
maximum
produc/vity
with
minimum
wasted
effort
or
expense
ar
Sports
car
1-­‐Liter
c
›
Measuring
Efficiency
›
Time
to
complete
the
›
Percentage
or
number
task
of
errors
›
Time
to
learn
›
Time
spent
on
error
Source:
hfp://www.usabilitymetrics.com/usability-­‐metrics.html

17. Usability:
sa/sfac/on
•
Sa/sfac/on
› Defini7on:
Fulfillment
in
one’s
expecta/ons,
needs,
or
pleasure
derived
from
this
›
Measuring
Sa7sfac7on
› Ra7ng
scale
for
› Number
of
7mes
user
sa7sfac7on
with
expresses
frustra7on
or
func7ons
and
features
anger
› Ra7ng
scale
for
usefulness
of
the
product
or
service
Source:
hfp://www.usabilitymetrics.com/usability-­‐metrics.html

18. Usability:
sa/sfac/on
Exper
ience
•
Sa/sfac/on
› Fulfillment
in
one’s
expecta/ons,
needs,
or
pleasure
derived
from
this
Keep
users
happy
by
allowing
for
flow

19. What
is
flow
?
Exper
ience
•
Flow
is
the
mental
state
of
opera7on
in
which
a
person
in
an
ac7vity
is
fully
immersed
in
a
feeling
of
energized
focus,
full
involvement,
and
success
in
the
process
of
the
ac7vity
How
to
allow
for
flow
?
(Some
principles)
•
The
user
must
have
a
clear
goal
•
Task
should
be
doable/workable
•
(Inter)ac7ons
should
have
immediate
feedback
In
So:ware
?
(Some
principles)
• Direct,
don’t
discuss
• Keep
tools
close
at
hand
• Provide
modeless
feedback
Sources:
About
Face
2.0,
Cooper,
Reiman,
The
Psychology
of
Op7mal
Experience;
Csikszentmihalyi

20. Flow
?

21. Allowing
for
flow
search

22. Allowing
for
flow
search

23. Allowing
for
flow
search

24. Allowing
for
flow
search

25. Allowing
for
flow
search

26. Allowing
for
flow
save

27. Allowing
for
flow
save

28. Allowing
for
flow
save
Demo
textedit

29. Allowing
for
flow

30. Allowing
for
flow

31. Allowing
for
flow

32. Allowing
for
flow

33. Allowing
for
flow
• Flow
!=
Workflow
› Flow
links
Workflows
› Flow
allows
uninterrupted
Work
› Think
ahead
for
your
user
???

34. Usability:
efficiency
•
Efficiency
› Achieving
maximum
produc/vity
with
minimum
wasted
effort
or
expense
To
make
a
product
more
efficient
one
can
reduce
TIME
and
WORK
“recall
of
passwords,
command
vectors,
names
and
loca7ons
of
data
objects
and
controls,
and
other
rela7onships
between
objects”
Mnemonic
Work
“decoding
visual
layouts
and
seman7cs
of
shape,
size,
color,
and
Perceptual
Work
representa7on”
“comprehension
of
text
and
organiza7onal
structures”
Logical
Work
“number
of
keystrokes,
degree
of
mouse
movement,
use
of
gestures,
Physical/Motor
switching
between
input
modes…”
Work
Source:
About
Face
2.0,
Cooper,
Reimann

35. Reducing
perceptual
work
?
• (Some)
Dimensions
of
visual
coding
› Posi7on
› Color
› Texture
› Shape
› Size
Source:
Productergonomie,
H.
Dirken

36. Reducing
perceptual
work
?
Proximity
• Elements
that
are
close
together
tend
to
be
perceived
as
a
group
(belonging
together)
Similarity
• Elements
with
similar
proper/es
(e.g.
shape,
color)
tend
to
be
perceived
as
groups

37. Reducing
perceptual
work

38. Reducing
perceptual
work

39. Reducing
perceptual
work

40. Reducing
perceptual
work

41. Reducing
perceptual
work

42. Reducing
perceptual
work

43. Reducing
perceptual
work
10 px 30 px
1.
Label Textfield next Label
2. Label always at the beginning of a new line

44. Reducing
perceptual
work
I meant in an intelligent way :-)

45. Reducing
perceptual
work

46. Reducing
perceptual
work

47. Reducing
perceptual
work
YES
!
this
is
the
same
as
the
one
above
J

48. Reducing
perceptual
work

49. Reducing
perceptual
work
• mandatory
• static
• easy to
overlook

50. Reducing
perceptual
work

51. Reducing
perceptual
work
no longer
mandatory

52. Reducing
perceptual
work

53. Reducing
perceptual
work
• errormarker

54. Reducing
perceptual
work

55. Reducing
perceptual
work

56. Reducing
perceptual
work

57. Reducing
perceptual
work
ambiguous
meaning of
disabled

58. Reducing
perceptual
work
better ?
what about the label ?

59. Recap
Defini/on
of
Usability
"The
extent
to
which
a
product
can
be
used
by
specified
users
to
achieve
specified
goals
with
effec1veness,
efficiency,
and
sa1sfac1on
in
a
specified
context
of
use.”
“Gest alt”
Laws
Flow
Do
not
interrupt
this
Mind
this
Source:
ISO
9241-­‐11

60. The
ques/on
is
?
How
do
users
experience
YOUR
so:ware
?
Who
are
my
What
are
What
is
the
users
?
their
goals
?
context
of
use
?
How
can
I
make
their
work
How
can
I
make
their
work
more
efficient
?
effec/ve
?
How
can
I
make
their
work
more
sa/sfying
?

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