Introduction to SPSS
Edward A. Greenberg, PhD
ASU HEALTH SOLUTIONS DATA LAB
JANUARY 7, 2013
Files for this workshop
Files can be downloaded from:
http://www.public.asu.edu/~eagle/spss
or (with less typing):
http://tinyurl.com/aa8crpn
SPSS Overview
• SPSS Statistics is a software package
used for statistical analysis.
• It is now officially named "IBM SPSS
Statistics".
• SPSS uses a graphical user interface.
• Most operations are “point and click”.
Availability of SPSS
• Installed on most Health Solutions
faculty and staff computers
• Available via MyApps for installation on
faculty, staff and student computers via
University site license
• Run in ASU Online Applications
environment (Citrix) via MyApps
• ASU Computing Sites on all campuses
Basic Steps in Data Analysis
• Get your data into
SPSS Statistics
SPSS can read data from a variety of
sources.
• Prepare your data set
for analysis
Set variable attributes, clean your data
and apply any needed transformations.
• Select a procedure
Select a procedure from the menus to
calculate statistics or to create a chart.
• Select the variables for
the analysis
The variables in the data file are
displayed in a dialog box for the
procedure.
• Run the procedure and
look at the results
Results are displayed in the Viewer.
Getting Data into SPSS Statistics
• Open a previously saved SPSS
Statistics data file
• Read another type of file
– Spreadsheet
– Database
– Text data file
• Enter your data directly in the SPSS
Data Editor
SPSS Data Files
The SPSS Data Editor window has two
views.
• Data View shows a spreadsheet of
cases (rows) and variables (columns).
• Variable View displays the metadata
dictionary, where each row represents
a variable and shows the variable
name, type, and other attributes.
SPSS Data Editor
Data View
SPSS Data Editor
Variable View
Variable Attributes
ATTRIBUTE
DESCRIPTION
Name
Variable name
Type
Data type
Width
Number of digits or characters
Decimals
Number of decimal places
Label
Descriptive variable label
Values
Descriptive value labels
Missing
User‐defined missing values
Columns
Column width
Align
Alignment
Measure
Measurement level
Role
Role assignment
Variable Attributes
VARIABLE NAME
• Variable names must be unique.
• Variable names may be up to 64
characters in length.
• Names can contain letters, numbers, or
special characters.
• Names must start with a letter or @, #,
or $.
Variable Attributes
DATA TYPE
• Numeric
–
–
–
–
40 character maximum length
Integers or numbers with decimals
Dates and times (various formats)
Other variations of numeric (currency,
comma, scientific notation, etc.)
• String
– 32,767 maximum length
– Can contain any characters
Variable Attributes
VARIABLE WIDTH
• For numeric variables, the width of the
number that is displayed.
• String variables can be up to 32,767
characters long.
Variable Attributes
DECIMALS
• Number of decimal places displayed for
numeric variables
• Allowable values are 0 thru (width-1)
Variable Attributes
VARIABLE LABEL
• A descriptive label for a variable
• Up to 255 characters in length
• Variable labels can contain spaces and
reserved characters that are not
allowed in variable names.
Variable Attributes
VALUE LABELS
• You can assign descriptive labels for
each value of a variable
• Particularly useful if your data file uses
numeric codes to represent nonnumeric categories (for example, codes
of 1 and 2 for male and female)
• Value labels can be up to 120
characters.
Variable Attributes
MISSING VALUES
• Allows you to distinguish between data that are
missing for different reasons.
• You can specify up to three discrete
(individual) missing values, a range of missing
values, or a range plus one discrete value.
• Missing values are excluded from most
calculations.
• By default, an empty cell for a numeric variable
is treated as missing.
Variable Attributes
COLUMN WIDTH
• The display width of a variable in the Data
Editor
• Affects only the display of values in the
Data Editor
• Does not change the defined width of a
variable.
• Column widths can also be changed in
Data View by clicking and dragging the
column borders.
Variable Attributes
ALIGNMENT
• Controls the display of data values
and/or value labels in Data View
• The default alignment is right for
numeric variables and left for string
variables.
• This setting affects only the display in
Data View.
Variable Attributes
LEVEL OF MEASUREMENT
LEVEL
DESCRIPTION
Nominal
Values represent categories with no intrinsic ranking.
Ordinal
Values represent categories with some intrinsic
ranking.
Scale
Values represent ordered categories with a
meaningful metric, so that distance comparisons
between values are appropriate.
Variable Attributes
ROLE
• Some dialogs support predefined roles
that can be used to pre-select variables
for analysis.
• Roles include Input (the default),
Target, Both, None and several others.
Data Transformations
The Transform menu includes routines which
perform transformations on selected variables.
These include the following, among others:
TRANSFORMATION
DESCRIPTION
COMPUTE
Compute values for a variable based on
numeric transformations of other variables
COUNT
Creates a numeric variable that, for each case,
counts the occurrences of the same value
(or list of values) across a list of variables
RECODE
Allows you to reassign the values of existing
variables or collapse ranges of existing
values into new values for a new or existing
variable
Running Procedures
• Most procedures are accessed via the
Analyze menu.
• Procedures are grouped according to
type, e.g., Reports, Descriptive
Statistics, Compare Means, Tables,
General Linear Model, and so on.
Running Procedures
Dialog boxes for statistical procedures and
charts typically have two basic components:
• Source variable list
A list of variables in the active dataset. Only
variable types that are allowed by the selected
procedure are displayed in the source list.
• Target variable list(s)
One or more lists indicating the variables that
you have chosen for the analysis, such as
dependent and independent variable lists.
SPSS Viewer
Results are displayed in the Viewer
SPSS Help and Other Resources
SPSS Help Menu
SPSS Help and Other Resources
• Tutorial videos (in Flash format) are available from
Central Michigan University at
http://calcnet.mth.cmich.edu/org/spss/toc.htm
• Raynald Levesque maintains an excellent
SPSS‐related web site with many helpful resources
at http://www.spsstools.net/
• The CONHI Data Lab can help you with SPSS: NHI1
391, CONHISTAT@ASU.EDU, (602) 496‐DATA*
• Many excellent books are available on SPSS
* Email probably is the best way to reach us