LAB 7 – INTRODUCTION TO STATISTICAL COMPUTING WITH SPSS
Purpose
Computers have revolutionized many aspects of society, including the process of conducting scientific
research. Before the arrival of the computer age, some of the statistical procedures that we’ll be
discussing, such as “factor analysis,” were impossible or could literally take months to conduct. Today,
the computations involved in a factor analysis usually take only seconds.
There are only a few steps in any kind of basic data analysis using a statistical software package:
1) Getting the stat package to read the raw data that has been collected from a study
 Creating a new data set (entering raw data, naming the variables, saving the data set)
 Opening a data set that has already been created and saved.
2) Performing any data manipulations that are necessary (eg, scoring questionnaires, “recoding”
variables, selecting sub-samples of participants to use for the analyses)
3) Conducting the statistical analyses that are appropriate for answering the research question.
4) Interpreting the output from the statistical analyses
The purpose of this lab is to introduce you to SPSS, which is one of the most widely-used stat packages in
Psychology. During this lab, we will cover issues from the first two (or maybe all four) steps described
above.
In “real life” (that is, when you actually collect and analyze data) you will use computers to conduct your
statistical analyses. But the very best way to obtain a deep understanding of what the statistics actually
mean is to have experience computing them by hand (or at least by hand and calculator). Therefore, the
preparatory assignment for today’s lab will give you experience computing and thinking about some very
basic statistics.
Preparation
1. Write your answers to the questions. Please show all work (formulas, each step of the
computations, etc): Pagano: ch 1 – questions 6c, 6d; ch 2 – questions 9a, 9b, 13b
2. Read the “Norms for a spelling test” assignment, and complete all of the questions.
Bring your computer to lab. Make sure that you can find and start-up SPSS.
Lab Session
Q & A’s about lecture
Go over the homework assignment, turn in the assignment
Begin working with SPSS (see the next page for an outline of the exercises).
Lab 7 SPSS Exercises
Enter the data
1. Get summary of responses to questionnaires
2. Open SPSS.
3. Notice the spreadsheet format – rows and columns. Usually when we enter data, each participant
will be a row and each variable will be a column. Thus, all of a participant’s information will be
entered onto one row, and each participant will have a separate row.
4. Prepare the SPSS spreadsheet so that you can enter the data.
a. You will have the following 10 variables: SWL item 1, SLW item 2, SWL item 3 ,SWL
item 4, SWL item 5, STAI item 1, STAI item 2 STAI item 3, STAI item 4, Gender.
b. Create variables info. In the “variable view” window,
i. Enter the name, type, and label for each variable that you will enter (eg, name =
“SWL1,” label = “Life is ideal”).
ii. Enter the value labels for the “Greek” variable (let’s say Yes = 1 and No = 0)
5. Enter data from response summaries: Go to the “data view” window and enter each participant’s
responses to each variable.
6. Save the data file.
Manipulate the data (Creating total scale scores)
1. Create scale scores for SWLS
a. Transform  Compute.
b. In “Target Variable” box, type the name of the new variable that will be created to
represent the total scale score on the SWL scale, say “SWLTotal”
c. In the “Numeric expression” box, enter the way that the new variable will be created.
Let’s compute the mean of the 5 SWL items. So, type “Mean(SWLS1, SWLS2, SWLS3,
SWLS4, SWLS5)”
2. Create scale scores for STAI
a. Note that one of the items is negatively-keyed, and it needs to be reverse-scored before
we go any further. See the handout on reverse-scoring
b. Transform  Compute.
c. In “Target Variable” box, type the name of the new variable that will be created to
represent the total scale score on the STAI scale, say “STAITotal”
d. In the “Numeric expression” box, enter the way that the new variable will be created.
Let’s compute the mean of the 5 STAI items. So, type “Mean(STAI1, STAI2, STAI3,
STAI4)”
Analyze data
1. Visually inspect the distribution of each variable (freq dist, hist, stem leaf)
a. Analyze  Descriptive Statistics  Frequencies (select SWLTotal, STAITotal, and
gender)
b. Interpret the output
c. Analyze  Descriptive Statistics  Explore (select variables and several stats and plots)
d. Interpret the output