Predictive Analytics Software:
What Statistics Can Do for You
Brett Deneckere
Dr. Kimberly Dodson
April 26, 2011
A “Living Legend” Production
Why Do We Use Statistics In
Research?
• To understand the professional literature,
• To understand the rational underlying
research in the behavioral sciences, and
• To conduct behavioral science research:
– Explaining, predicting, and controlling social behavior.
– Tentative conclusions about the existence and strength of
social relationships.
What Are Statistics?
• The recording, organizing, analyzing, and
reporting of quantitative information;
• A collection of numerical data that measure
something; and
• Numerical tools used by researchers to help
them describe and explain phenomena.
Descriptive Statistics
• Descriptive statistics show the relationship
between variables.
• They are used to describe and summarize a
particular data set.
Creating a Bar Graph
How do you create
a graph? graph
Well Doc, it’s actually
not that hard. Let me
show you!
Select “Graphs”
from the Menu
Select “Legacy
Dialogs”
Select the “Bar
Chart” Option
Select the
“Simple” option
Click “Define”
Select a
variable
from the list.
Your selected
variable
appears here
Click OK and…
SHAZAM! Bar Graph
Testing Relationships
What analysis would
you use to find out
if two variables are
related? graph
Well Doc, that would
depend on the level
of measurement of
your variables!
Variables
• Variable type is important to determine the level of
measurement and the techniques available to
analyze data.
– Continuous
• Can assume an infinite number of values
– Examples: time, age, length
– Discrete
• Can assume only a finite number of whole unit values
– Examples: sex, political affiliation, number of children in a
family
Levels Of Measurement
• Nominal
– Variables can be placed in mutually exclusive,
exhaustive categories, but can’t be ordered any
further.
• Languages: English, Spanish, Chinese, Klingon
• Ordinal
– Variables can be categorized as well as ranked
according to the degree to which a certain
attribute is present
• I love my mother: Strongly Agree, Agree, Neutral,
Disagree, Strongly Disagree
Levels Of Measurement
• Interval
– A scale with an arbitrary zero point, but equal
distance (intervals) between any two adjacent
units.
• Temperature in Celsius: 1°-100°
• Ratio
– Contains all the properties of the first three levels,
but with an inclusion of an absolute zero point.
• How much money is in your pocket: $4, $12, $20,
$7,596
NO
Can the data be
ordered?
Nominal
YES
NO
Are there equal
intervals?
Ordinal
YES
NO
Is there a true
zero?
Interval
YES
Ratio
Process for determining level of measurement
Adapted from: Walker, J. (1999). Statistics in
Criminal Justice. Gaithersburg, Maryland:
Aspen.
Testing Relationships
What if we wanted
to examine the
graph
relationship
between gender
and tobacco use ?
Let’s run a simple
crosstabs to answer
that question!
Select
“Analyze” from
the Menu
Select
“Descriptive
Statistics”
Select the
“Crosstabs” Option
Select the
Variables you
want to Examine
Click “OK”
Your Variables will
Appear Here
Hit “Continue”
and…
Boom Boom Pow! A
Crosstabulation
Crosstabs Results
• The results indicate that males (54%) are more
likely than females (32%) to use tobacco.
• Cramer’s V tells us the strength and direction
of the relationship between two nominal level
variables.
• There is a weak positive relationship between
gender and tobacco use with males reporting
more use than females.
Testing Relationships
What if we wanted
to know
if gender
graph
is related to binge
drinking?
Let’s run a simple
bivariate correlation
to answer that
question!
Bivariate Correlation
• Bivariate correlation is a statistical technique
that gives us the strength and direction of a
relationship between two variables.
Select “Analyze”
from the menu
Select the
“Correlate” option
Select the “Bivariate”
option
Select your variables
Both of your variables
will appear here
Click “OK” and…
WHOOPAH!
A Bivariate Correlation
Chart
Bivariate Correlation
Results
• There is a weak positive relationship between
gender and binge drinking (r = .26, p = .01).
• In other words, males are more likely to binge
drink than females.
Conclusions
This is Heavy!
Great Scott!
Statistics are powerful!