1.
Predic've
Analy'cs
with
UX
Research
Data:
Yes
We
Can!
Mike
Fritz
Paul
Berger
UXPA
BOSTON
2015
1

2.
Paul
Berger
Visi'ng
Scholar
and
Professor
of
Marke'ng,
and
Academic
Director
of
Master
of
Science
in
Marke'ng
Analy'cs,
Bentley
University
Ph.D.
Sloan
School,
MIT
Mike
Fritz
Manager
of
Usability
and
User
Experience
Research
PeopleFluent
MS
in
Human
Factors
in
Informa'on
Design
Bentley
University
Who
We
Are
2

3.
Our
book:
March
2015
3

4.
What
we’re
going
to
discuss
today
• Basic
(and
not
so
basic)
predic've
analy'cs
you
can
apply
to
the
data
you’re
collec'ng
today!
• We’ll
show
examples
using
data
garnered
from
moderated
and
unmoderated
usability
tests
and
surveys.
• Confidence
Intervals
• Correla'on
• Simple
Linear
Regression
• Stepwise
Regression
• We’re
going
to
concentrate
on
usability
and
survey
data,
but
you
can
apply
these
techniques
to
all
kind
of
data
that
you
might
collect
using
different
methods:
interviews,
focus
groups,
card
sor'ng,
contextual
inquiries,
and
even
physiological
tes'ng,
such
as
eye
tracking,
heart
rate
variance
and
skin
conductance.
4

5.
Confidence
Intervals
5

6.
Confidence
Intervals:
A
good
way
to
depict
them:
6
Put
simply,
a
confidence
interval
is
an
interval
which
contains
a
popula'on
value,
such
as
the
popula'on
mean,
with
some
specified
probability,
usually,
0.95
or
95%.

7.
Confidence
Intervals
7
• Confidence
intervals
are
extremely
useful—and
even
cri'cal—to
any
UX
researcher.
• In
fact,
it’s
easy
to
make
a
case
that
construc'ng
a
confidence
interval
is
even
more
important
when
you
have
a
small
sample
size.
• And,
indeed,
that’s
exactly
what
we
have
in
most
usability
datasets.
• However…consider
the
following:

8.
How
is
preparing
for
a
usability
test
and
making
a
big
bowl
of
chili
for
Sunday’s
football
game*
the
same?
*with
or
without
Tom
Brady

9.
It’s
almost
the
same
amount
of
work
gehng
ready
for
4….or
8.
9
So
you
might
as
well
“serve”
8,
because……

10.
You
will
be
able
to
report
out
your
findings
with
a
LOT
more
sta's'cal
authority!
10

11.
Usability
Tes'ng:
It’s
all
about
the
prep
'me……
• The
prepara'on
for
crea'ng
and
preparing
a
test
for
4
versus
8
is
almost
the
same.
That
is,
it’s
the
same
amount
of
work
to
write
up
a
test
plan,
define
the
tasks,
get
consensus
on
the
tasks,
and
coordinate
the
assets
for
the
test
whether
you’re
tes'ng
for
4
or
8.
• Admiledly,
it’s
going
to
take
longer
to
recruit
and
actually
run
the
tests,
but
it’s
probably
a
difference
of
only
one
day
of
tes'ng.
11

12.
Example:
Likert
Scale
with
8
par'cipants
12
• Let’s
assume
you’ve
just
finished
running
a
usability
test
for
an
online
shoe
store.
• Aner
the
test,
par'cipants
are
asked
to
rate
their
agreement
with
the
statement
“Finding
running
shoes
in
my
size
is
easy”
on
a
scale
of
1
to
5,
where
1
=
Strongly
Disagree
and
5
=
Strongly
Agree.
• Let’s
assume
that
there
was
an
even
split
between
“3”s
and
“4”s
(4
each)
for
an
average
of
3.5.
•
The
resul'ng
95%
confidence
interval
for
the
true
mean
ra'ng
of
3.5
±
0.45.

13.
Example:
Likert
Scale
with
4
par'cipants
13
• Now
assume
that
you
ran
the
same
test
with
only
4
par'cipants.
• Again,
aner
the
test,
par'cipants
are
asked
to
rate
their
agreement
with
the
statement
“Finding
running
shoes
in
my
size
is
easy”
on
a
scale
of
1
to
5,
where
1
=
Strongly
Disagree
and
5
=
Strongly
Agree.
• Again,
let’s
assume
that
there
was
an
even
split
between
“3”s
and
“4”s
(2
each).
This
&me,
you
s&ll
have
an
average
of
3.5,
but
now
your
confidence
interval
has
more
than
doubled
in
width
to
3.5
±
0.92!

14.
Confidence
Intervals:
Sample
Size
of
4
versus
8
14

15.
Correla'on
15

16.
Correla'on
16
• The
“correla'on
coefficient”
reflects
the
rela'onship
between
two
variables.
• Specifically,
it
measures
the
strength
of
a
straight-­‐line
rela'onship
between
two
variables,
and
also
tells
you
the
direc'on
of
the
rela'onship,
if
any.
It
is
a
numerical
value
that
ranges
between
−1
and
+1
and
is
typically
denoted
by
“r”:
−
1
≤
r
≤
+
1

17.
Correla'on
Scenario
Scenario
• You’re
a
usability
researcher
at
Behemoth.com,
an
employment
Web
site.
• The
main
source
of
Behemoth’s
income
is
from
employers
who
post
jobs
on
the
site
and
buy
access
to
its
enormous
database
of
over
a
million
resumes
to
search
for
good
candidates
to
fill
those
jobs.
• The
candidate
search
engine
is
not
great,
and
is
only
effec've
for
those
savvy
recruiters
who
know
how
to
construct
clever
Boolean
search
strings
that
yield
results
that
get
them
what
they
want.
17

18.
Correla'on
Scenario
Scenario(cont.)
• You
hear
from
the
grapevine
that
Behemoth
is
about
to
spend
80
million
dollars
on
a
brand
new
“Turbo
Search”
(built
by
a
Palo
Alto
start-­‐up)
that
will
“fundamentally
change
the
way
recruiters
search
for
candidates
through
its
algorithm
that
searches
for
people,
not
keywords.”
• What’s
the
rub?
Turbo
will
kill
Boolean
search!
Dissension
in
the
ranks:
“Will
recruiters
abandon
us
if
we
abandon
Boolean
search?”
18

19.
19

20.
Correla'on
Scenario
Your
Challenge:
Determine
whether
killing
Boolean
capability
is
a
mistake
before
Behemoth
blows
$80
million
on
a
new
search
engine!
20

21.
Correla'on
Methodology
1. Launch
unmoderated
usability
test
of
the
current
Behemoth
search
engine
to
about
300
recruiters.
All
the
respondents
are
tasked
with
finding
good
candidates
for
the
same
three
requisi'ons.
2. Aner
comple'ng
the
tasks
of
finding
candidates
for
the
three
posi'ons,
the
par'cipants
are
asked
to
rate
their
percep'on
of
usefulness
for
each
of
the
15
fields
in
the
search
engine,
on
a
scale
of
1–5,
where
1
=
not
at
all
useful
and
5
=
extremely
useful.
3.
Calculate
the
correla'on
coefficient
between
the
usefulness
of
the
ability
to
perform
a
Boolean
Search
and
the
likelihood
of
adop'on
of
the
Search
engine.
21

22.
Rated
Search
Engine
Components
1.
Ability
to
search
by
job
'tle
2.
Ability
to
search
by
years
of
experience
3.
Ability
to
search
by
loca'on
4.
Ability
to
search
by
schools
alended
5.
Ability
to
search
candidates
by
date
of
updated
resume
6.
Ability
to
search
candidates
by
level
of
educa'on
7.
Ability
to
search
by
skills
8.
Ability
to
search
candidates
by
average
length
of
employment
at
each
company
9.
Ability
to
search
candidates
by
maximum
salary
10.Ability
to
search
candidates
by
job
type
he/she
is
looking
for:
full
'me,
part
'me,
temporary/contract,
per
diem,
intern
11.Ability
to
search
candidates
by
companies
in
which
they
have
worked
12.Ability
to
search
candidates
by
willingness
to
travel.
(Expressed
as
“no
travel
ability
required,”
“up
to
25%,”
“up
to
50%,”
“up
to
75%,”
“up
to
100%”)
13.Ability
to
search
candidates
by
willingness
to
relocate
14.Ability
to
search
candidates
by
security
clearance.
(Ac've
Confiden'al,
Inac've
Con-­‐
fiden'al,
Ac've
Secret,
Inac've
Secret,
Ac've
Top
Secret,
Inac've
Top
Secret,
Ac've
Secret/
SCI,
Inac've
Top
Secret/SCI)
15.
Ability
to
perform
a
Boolean
search
22

23.
Dependent
Variable
Methodology:
3.
At
the
very
end
of
the
survey
ra'ng,
you
insert
the
dependent
variable
ques'on(y):
“Imagine
that
this
search
engine
is
available
to
you
at
no
cost
to
find
qualified
candidates
using
the
candidate
databases
you
currently
employ.
Rate
your
likelihood
of
adopGng
this
candidate
search
engine
on
a
scale
of
1–5,
where
1
=
not
at
all
likely
and
5
=
extremely
likely.”
23

24.
Correla'on
Methodology:
Excel
Screen
Shot
24

25.
Correla'on
Methodology:
Excel
Screen
Shot
25
• We
can
see
that
the
correla'on
coefficient
is
+0.449.
What
this
tells
us
is
that
a
higher
sense
of
usefulness
of
a
Boolean
search
capability
is
associated
with
a
higher
likelihood
of
adop'on
of
the
search
engine.
• This
also
says
that
20.2%
(100
*
(.449)
^
2)
of
the
variability
in
likelihood
of
adop'on
of
the
search
engine
is
explained
by
a
recruiter’s
assessment
of
the
usefulness
of
having
a
Boolean
search
available.
We
can
also
determine
the
specific
rela'onship
between
the
2
variables:

26.
Linear
Regression
26

27.
Linear
Regression
27
• The
fundamental
purpose
of
regression
analysis
is
to
study
the
rela'onship
between
a
“dependent
variable”
(which
can
be
thought
of
as
an
output
variable)
and
one
or
more
“independent
variables”
(which
can
be
thought
of
as
input
variables).
• A
linear
regression
analysis
will
determine
the
best
fihng
slope
and
intercept
of
a
linear
rela'onship.
• In
this
scenario,
we
will
have
one
independent
variable—
this
form
of
regression
is
called
“simple
regression.”
• In
our
next
scenario,
we
will
have
several
input/
independent
variables
(i.e.,
X’s)—this
will
be
called
“mul'ple
regression.”

28.
Linear
Regression
Methodology:
Excel
Screen
Shot
28

29.
Linear
Regression
Methodology:
Excel
Screen
Shot
29

30.
Results
• The
very
low
p-­‐value(less
than
once
chance
in
a
billion!)
indicates
that
there
is
virtually
no
doubt
that
there
is
a
posiGve
linear
relaGonship
between
the
usefulness
of
the
Ability
to
do
a
Boolean
search,
and
the
Likelihood
of
AdopGon
of
the
search
engine.
•
Furthermore(and
as
noted
earlier),
the
r-­‐square
value
of
0.202
means
we
es'mate
that
the
usefulness
of
Boolean,
by
itself,
explains
more
than
20%
of
the
responder’s
choice
for
the
Likelihood
of
Adop'on
of
the
search
engine
query.
• The
best
fihng
(or
“least
squares”)
line
is
Yp=2.4566
+
0.460
*
X
Example:
if
X=3,
Yp=3.84
30

31.
Example
2
Stepwise
Regression
31

32.
Stepwise
Regression
• Your
results
trickle
upwards
in
the
managerial
chain.
Your
CEO,
Joey
Vellucci,
exasperated
by
all
the
nega've
news
that
always
comes
from
the
usability
lab,
proclaims
to
his
VP
of
development:
“These
UX
folks
remind
me
of
Agnew’s
‘naUering
nabobs
of
negaGvism’.
Why
don’t
they
come
up
with
their
own
ideal
search
engine
instead
of
just
finding
problems
all
the
Gme
in
the
lab?”
32

33.
Stepwise
Regression
Challenge
Accepted!
Stepwise
Regression
to
the
Rescue!
33

34.
For
those
of
you
born
way
aner
Watergate:
34

35.
Linear
Regression
Methodology
To
refresh
your
memory:
1.
You
launched
an
unmoderated
usability
test
of
the
current
Behemoth
search
engine
to
about
300
recruiters.
All
the
respondents
were
tasked
with
finding
good
candidates
for
the
same
three
requisi'ons.
2.
Aner
comple'ng
the
tasks
of
finding
candidates
for
the
three
posi'ons,
the
par'cipants
are
asked
to
rate
their
percep'on
of
usefulness
for
each
of
the
15
fields
in
the
search
engine,
on
a
scale
of
1–5,
where
1
=
not
at
all
useful
and
5
=
extremely
useful.
35

36.
Stepwise
Regression
Example
3.
At
the
very
end
of
the
survey
ra'ng,
you
insert
the
moment
of
truth
ques'on:
“Imagine
that
this
search
engine
is
available
to
you
at
no
cost
to
find
qualified
candidates
using
the
candidate
databases
you
currently
employ.
Rate
your
likelihood
of
adopGng
this
candidate
search
engine
on
a
scale
of
1–5,
where
1
=
not
at
all
likely
and
5
=
extremely
likely.”
36

37.
Stepwise
Regression
Example
• Stepwise
regression
is
a
varia'on
of
regular
mul'ple
regression
that
was
invented
to
specifically
address
the
issue
of
variables
that
overlap
a
lot
in
the
informa'on
they
provide
about
the
“Y”
(the
output
variable).
• It’s
an
automated
process
that
brings
variables
in
(and
once
in
a
while
out)
of
the
equa'on
one
at
a
'me.
37

38.
The
beauty
of
stepwise
regression!
Stepwise
regression
has
2
excellent
quali'es:
1)All
variables
in
the
final
equa'on
are
sta's'cally
significant.
2)It
is
guaranteed
that
there
are
no
variables
not
in
the
equa'on
that
would
be
sta's'cally
significant.
38

39.
Stepwise
Regression
Example:
SPSS
Screen
Shots
39

40.
Stepwise
Regression
Example:
Screen
Shots
40

41.
Stepwise
Regression
Example:
Screen
Shots
41

42.
Sta's'cally
significant
variables
42
• Ability
to
perform
a
Boolean
search
• Ability
to
search
by
skills
• Ability
to
search
by
job
'tle
• Ability
to
search
candidates
by
companies
in
which
they
have
worked
• Ability
to
search
by
loca'on
• Ability
to
search
by
years
of
experience
• Ability
to
search
candidates
by
level
of
educa'on

43.
Stepwise
Regression
Example
Yc
=
0.528
+
0.311
*
X15
+
0.177
*
X7
+
0.121
*
X11
+
0.153
*
X1
+
0.106
*
X
+
0.106
*
X2
+
0.055
*
X6,
or,
if
we
order
the
variables
by
subscript,
Yc
=
528
+
0.153
*
X1
+
0.106
*
X2
+
0.106
*
X3
+
0.055
*
X6
+
0.177
*
X7
+
0.121
*
X11
+
0.311
*
X15.
In
other
words,
this
equa'on
says
that
if
we
plug
in
a
person’s
value
for
X1,
X3,
X6,
X7,
X11,
and
X15,
we
get
our
“best”
model
for
predicGng
what
the
person
will
choose
for
Y,
the
likelihood
on
the
5-­‐point
scale
that
he/
she
will
adopt
the
search
engine.
AND,
NOTE
THAT
ALL
THE
COEFFICIENTS
ARE
POSITIVE!!
43

44.
Stepwise
Regression
Example:
Recommenda'ons
For
your
recommenda'ons,
you
produce
a
wireframe
that
illustrates
the
user
interface
for
a
new
search
home
page:
1.
Your
new
design
shows
a
two-­‐'ered
system;
a
“basic
search”
includes
the
top
seven
variables
iden'fied
as
significant
in
your
stepwise
regression
analysis.
2.
If
desired,
the
user
can
click
on
“Advanced”
search
to
reveal
the
remaining
eight
variables.
Even
though
they
were
not
staGsGcally
significant,
and
cannot
be
said
to
“add
to
the
story,”
they
nevertheless
might
be
useful
for
certain
recruiters
looking
for
a
very
specific
set
of
qualifica'ons.
44

45.
Stepwise
Regression
Example:
CEO
LIKES
IT!
45

46.
Our
book:
March
2015
46

47.
What
we
show
you
how
to
do
in
the
book.
• Prac'cal
Advice
on
choosing
the
right
data
analysis
technique
for
each
project
• A
step-­‐by-­‐step
methodology
for
applying
each
technique,
including
examples
and
scenarios
drawn
from
the
UX
field.
• Detailed
screen
shots
and
instruc'ons
for
performing
the
techniques
using
Excel(both
for
PC
and
Mac)
and
SPSS
• Clear
and
concise
guidance
on
interpre'ng
the
data
output
• Exercises
to
prac'ce
the
techniques,
along
with
access
to
sample
data
on
the
companion
website.
47

48.
Don’t
fear
the
future…
48

49.
Embrace
it!
49

50.
Predic've
Analy'cs
with
UX
Research
Data:
Yes
We
Can!
Mike
Fritz
Paul
Berger
UXPA
BOSTON
2015
50
mike.fritz@peoplefluent.com
pberger@bentley.edu
QUESTIONS?