SPSS stands for Statistical Package for the Social Sciences. It is a general purpose statistical and data  management program. There are many different things that SPSS can be used for, some of which you will learn in the methodology class. This document covers a few of the basics. If you continue on in political science or any of the social sciences (as well as the private sector such as in marketing research)  you will almost certainly learn more of either SPSS or SAS another popular statistical package. At  some point you may want to start the SPSS tutorial; this page will focus on some more specific issues.

How do I Start SPSS?

SPSS is a windows program. Look on the menu for Programs and click on it. Then click on SPSS icon.

What is on the screen when you first start SPSS?

When you first go into SPSS a screen will come up and  the first thing you will see is a blank spreadsheet (a grid of rectangles). The spread  sheet is where the data to be analyzed are stored. It is blank because you have not yet put any data in.

Along the top of the screen you will see a series of words:

File, Edit, Data, Transform, Statistics, Graphics, Help

This will be referred to as the main menu.

How do I open a pre-existing data set?

If you want to use a pre-existing dataset you click on File on the main menu, then select Data and
Open. This will give you a list of files called XXX.sav with the XXX a real name. Usually it will be the list of files on the k drive. If you see the file you want, double click on it.

How do I Run Simple Statistics?

To run simple statistics Click on statistics on the main menu,  then on summarize.   Frequencies will give you simple frequency distributions.  Descriptives will give you simple means. Crosstabs will give you tables.

All of the procedures follow the same basic pattern. On the left you will see a box with a list of
variables. On the right you will see an empty box or boxes (unless you have already run a procedure, in which case you will see what ever you did before). Between them you will see a gray square with a triangle. This is supposed to represent an arrow. If you click on a variable name in the left box and then click on the arrow, that variable will "move" to the right box (and vice versa.

If you are running a Cross Tabulation (crosstab) you will need to move a variable to the row box and another to the column box. (Conventionally, the independent variable goes in the columns and the dependent variable goes in the rows).

All of the procedures have various options that may be selected by clicking on various buttons.

When you are finished selecting the variables and any options, click on continue. The output from the program will appear in the "output window." To print the output file click on the picture of the printer.

What if I want to create a new data set?

To create a new data set you work in the black spread sheet that appears on the screen when you first open SPSS. There are several steps: Defining variables, entering the data, and saving the data.

Defining variables

The first step in inputting your new data set is to define each variable.  In general, each question in your questionnaire will correspond to a variable in SPSS.   If you are entering official statistics, each type of statistic (e.g. the monthly unemployment rate) will correspond to one variable in SPSS. Each variable is a column in the grid.

Generally, before starting to input your data you should go through your survey and number the
questions and within each question number the answers. It is also possible to use letters, but most
people find numbers easier.

Go to the first column and on the SPSS main menu select Data/Define Variable.

You will get a box that says Variable Name with an empty box next to it, some information, and then a box that says "Change Settings" with smaller "buttons" within it.

First, enter a variable name.  This should be a short--less than 8 characters-- but useful name. For
example AGELAST would be the variable name for age at last arrest. Or, EDUC would be the
variable name for years of education.

Adding labels

Next, add labels by clicking on the labels button within the Change Settings box. The variable label is a longer description of what the variable is about.  "Years of education" would be the variable label for EDUC.  "Age at last arrest" would be the variable label  for AGELAST.

In many cases you will want to add value labels.  These are descriptions of what each of the answers to the survey are. For example, if a person answers "strongly agree" that answer may be coded as a 5. However, you would still like the information about what 5 means to show up when you do statistical analysis, such as making tables.  In general you will not do variable labels for interval variables such as a person's years of age or number of children because the label would not provide any additional information.  To enter value labels, go into the Value Labels box. First enter the value (the number corresponding to the answer), then enter the label (what the answer means). So the value of 5 would correspond to a value label on strongly agree.   Then click on the Add button.  The label you entered will move into the box, and you can repeat the process until all of the values have labels.
 

Entering the Data

Each row in the grid will generally represent one observation, for example a single survey or
information on a single state.  After you  have defined the variables you simply type in the value for
each variable in the appropriate row and column.   You can either start with the first variable of the observation and work your way across the page to the last observation, then go to the next row and do the same for the second observation.  Or you can type in the first variable for every observation, then the second and so on.  Do which every is easier or more convenient.

Don't forget to proof read after entering data.

Saving the data set

When you have finished entering data, you can save the data set by clicking File/Save As and then
entering a data set name.  This should be xxxx.sav where you fill in the xxxx with something useful.  If you are working in the lab, make sure that you point the file to your floppy disk (the A:\).