SPSS Survival Manual: A Step-by-Step Guide to Data Analysis

S P S S S U R V I V A L M A N U A L
To Download the SPSS Survival Manual, go to www.bookfre.com

S P S S S U R V I V A L M A N U A L
A step by step guide to data
analysis using SPSS for Windows
(Version 10)
JULIE PALLANT

O P E NU N I V E R S I T Y P R E S S
B u c k i n g h a m • P h i l a d e l p h i a
SPSS is a trademark of SPSS Inc. for its proprietary computer software. This book is not
approved, sponsored or connected with SPSS Inc. Further information about SPSS is available
from:
SPSS Inc., 233 S. Wacker Drive, Chicago, Illinois USA 60606-6307 Tel: 1 (800)
543 2185, Fax: 1 (800) 841 0064
http://www.spss.com
Open University Press
Celtic Court
22 Ballmoor
Buckingham MK18
1 XW
email: enquiries@openup.co.uk
world wide web: www.openup.co.uk
and
325 Chestnut Street
Philadelphia, PA 19106, USA
First published in 2001
Copyright © Julie Pallant 2001
All rights reserved. Except for the quotation of short passages for the purposes of criticism and
review, no part of this publication may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, recording or otherwise,
without prior written permission of the publisher or a licence from the Copyright Licensing Agency
Ltd. Details of such licences (for reprographic reproduction) may be obtained from the Copyright
Licensing Agency Ltd of 90 Tottenham Court Road, London, W1P 9 HE.
A catalogue record of this book is available from the British Library
ISBN 0 335 20890 8
Library of Congress Cataloging-in-Publication Data available
Set in 11/14 pt Goudy by DOCUPRO, Canberra, Australia
Printed by McPherson’s Printing Group, Maryborough, Victoria
Contents
SPSS Survival Manual
Contents
Data files and website xi

Introduction and overview xii
Structure of this book xiii
Using this book xiii
Research tips xv
Additional resources xvi
PART ONE GETTING STARTED 1
1 Designing a study 3
Planning the study 3
Choosing appropriate scales and measures 5
Preparing a questionnaire 7
References 10
2 Preparing a codebook 12
Variable names 12
Coding responses 13
Coding open-ended questions 14
3 Getting to know SPSS 15
Starting SPSS 15
Working with data files 15
SPSS windows 18
Menus 22
Dialogue boxes 23
Closing SPSS 25
Getting help 25
PART TWO PREPARING THE DATA FILE 27
4 Creating a data file and entering data 29
Changing the SPSS ‘Options’ 29
Defining the variables 31
Entering data 36
Modifying the data file 37
Data entry using Excel 40
5 Screening and cleaning the data 42
Step 1: Checking for errors 42

vi
Step 2: Finding the error in the data file 45
Step 3: Correcting the error in the data file 47
References 48
PART THREE PRELIMINARY ANALYSES 49
6 Descriptive statistics 51
Categorical variables 51
Continuous variables 52
Assessing normality 54
Checking for outliers 59
References 62
7 Using graphs to describe and explore the data 63
Histograms 63
Bar graphs 64
Scatterplots 66
Boxplots 68
Line graphs 69
Editing a chart/graph 72
Importing charts/graphs into Word documents 73
8 Manipulating the data 74
Calculating total scale scores 74
Transforming variables 78
Collapsing a continuous variable into groups 81
References 84
9 Checking the reliability of a scale 85
Details of example 85
Procedure for checking the reliability of a scale 86
Interpreting the output from reliability 87
Presenting the results from reliability 87
References 87
10 Choosing the right statistic 89
Overview of the different statistical techniques 89
The decision-making process 93
Key features of the major statistical techniques 99

References
Summary table of the characteristics of the main statistical
104
techniques
PART FOUR STATISTICAL TECHNIQUES TO EXPLORE
106
RELATIONSHIPS AMONG VARIABLES 109
Techniques covered in Part Four 109
Summary for correlation 116
Preliminary analyses for correlation 117
Procedure for calculating Pearson product-moment correlation 118
Interpretation of output from correlation 119
Presenting the results from correlation 121
Obtaining correlation coefficients between groups of variables 122
Comparing the correlation coefficients for two groups
Testing the statistical significance of the difference between
124
correlation coefficients 126
References 129
12 Partial correlation 130
Summary for partial correlation 131
Procedure for partial correlation 131
Interpretation of output from partial correlation 132
Presenting the results from partial correlation 133
References 133
13 Multiple regression 134
Major types of multiple regression 135
Assumptions of multiple regression 136
Summary for multiple regression 139
Standard multiple regression 140
Revision of the basics 110
References 114
11 Correlation 115
Content
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viii
Hierarchical multiple regression 146
Presenting the results of multiple regression 149
References 150
14 Factor analysis 151
Steps involved in factor analysis 152
Summary for factor analysis 156
Procedure for factor analysis 157
Part 1: Assessing the data and extracting the factors 157
Part 2: Factor rotation and interpretation 162
Presenting the results of factor analysis 165
References 167
PART FIVE STATISTICAL TECHNIQUES TO
COMPARE GROUPS 169
Techniques covered in Part Five 169
Assumptions 170
Type 1 error, Type 2 error and power 172
Planned comparisons/Post-hoc analyses 173
Effect size 175
References 176
15 T-tests 177
Independent-samples t-test 177
Summary for independent-samples t-test 178
Procedure for independent-samples t-test 178
Interpretation of output from independent-samples t-test 179
Calculating the effect size for independent-samples t-test 180
Presenting the results for independent-samples t-test 181
Paired-samples t-test 181
Summary for paired-samples t-test 182
Procedure for paired-samples t-test 183
Interpretation of output for paired-samples t-test 183
Calculating the effect size for paired-samples t-test 184
Presenting the results for paired-samples t-test 185

References 185
16 One-way analysis of variance 186
One-way between-groups ANOVA with post-hoc tests 187
Details of example
Summary for one-way between-groups ANOVA with post-hoc
187
tests
Procedure for one-way between-groups ANOVA with post-hoc
188
tests
Interpretation of output from one-way between-groups ANOVA
188
with post-hoc tests 190
Calculating effect size
Presenting the results from one-way between-groups ANOVA
191
with post-hoc tests 192
One-way between-groups ANOVA with planned comparisons 192
Specifying coefficient values
Procedure for one-way between-groups ANOVA with planned
193
comparisons
Interpretation of output from one-way between-groups ANOVA
194
with planned comparisons 195
One-way repeated measures ANOVA 195
ANOVA 198
Presenting the results from one-way repeated measures ANOVA 199
References 200
17 Two-way between-groups ANOVA 201
Summary for two-way ANOVA 202
Procedure for two-way ANOVA 203
Interpretation of output from two-way ANOVA 205
Presenting the results from two-way ANOVA 207
Additional analyses if you obtain a significant interaction effect 207
References 208
18 Mixed between-within subjects analysis of variance 209
Details of examples 196
Summary for one-way repeated measures ANOVA 196
Procedure for one-way repeated measures ANOVA 197
Interpretation of output from one-way repeated measures
Content
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ix

x
Summary for mixed between-within ANOVA 210
Procedure for mixed between-within ANOVA 211
Interpretation of output from mixed between-within ANOVA 214
Presenting the results from mixed between-within ANOVA 216
References 216
19 Multivariate analysis of variance 217
Summary for one-way MANOVA 218
Assumption testing 219
Performing MANOVA 225
Interpretation of output from MANOVA 228
Presenting the results from MANOVA 231
References 232
20 Analysis of covariance 233
Uses of ANCOVA 233
Assumptions of ANCOVA 234
One-way ANCOVA 237
Summary for one-way ANCOVA 238
Testing assumptions 238
Procedure for one-way ANCOVA 243
Interpretation of output from one-way ANCOVA 244
Presenting the results from one-way ANCOVA 246
Two-way ANCOVA 246
Summary for two-way ANCOVA 248
Procedure for two-way ANCOVA 249
Interpretation of output from two-way ANCOVA 251
Presenting the results from two-way ANCOVA 253
References 254
21 Non-parametric statistics 255
Summary of techniques covered in this chapter 255
Chi-square 256
Mann-Whitney U Test 260

Wilcoxon Signed Rank Test 261
Kruskal-Wallis Test 263
Friedman Test 265
Spearman’s Rank Order Correlation 266
References 267
Appendix Details of data files 268
Part A: Materials relevant to survey.sav 270
Part B: Materials relevant to experim.sav 277
Recommended references 279
Index 283
Data files and website
Data files and website
Throughout the book you will see examples of research that are taken from two
data files included on the website that accompanies this book ( survey.sav,
experim.sav). This website is at:
www.openup.co.uk/spss To
access the data files directly, go to:
www.openup.co.uk/spss/data
From this site you can download the data files to your hard drive or floppy disk by
following the instructions on screen. Then you should start SPSS and open the data
files. These files can only be opened in SPSS.
The survey.sav data file is a ‘real’ data file, based on a research project that
was conducted by one of my graduate diploma classes. So that you can get a feel
for the research process from start to finish, I have also included in the Appendix a
copy of the questionnaire that was used to generate this data and the codebook
used to code the data. This will allow you to follow along with the analyses that are
presented in the book, and to experiment further using other variables. The second
data file (experim.sav) is a manufactured (fake) data file, constructed and
manipulated to illustrate the use of a number of techniques covered in Part Five of
the book (e.g., Paired Samples t-test, Repeated Measures ANOVA). This file also
includes additional variables that will allow you to practise the skills learnt

xii
throughout the book. Just don’t get too excited about the results you obtain and
attempt to replicate them in your own research!
Apart from the data files, the SPSS Survival Manual website also contains a
number of useful items for students and instructors, including:
• guidelines for preparing a research report;
• practice exercises;
• updates on changes to SPSS as new versions are released;
• useful links to other websites; • additional reading; and
• an instructor’s guide.

Introduction and overview
Introduction and overview
This book is designed for students completing research design and statistics
courses and for those involved in planning and executing research of their own.
Hopefully this guide will give you the confidence to tackle statistical analyses
calmly and sensibly, or at least without too much stress!
Many of the problems students experience with statistical analysis are due to
anxiety and confusion from dealing with strange jargon, complex underlying
theories and too many choices. Unfortunately, most statistics courses and
textbooks encourage both of these sensations! In this book I try to translate
statistics into a language that can be more easily understood and digested.
The SPSS Survival Manual is presented in a very structured format, setting out
step by step, what you need to do to prepare and analyse your data. Think of your
data as the raw ingredients in a recipe. You can choose to cook your ‘ingredients’
in different ways—a first course, main course, dessert. Depending on what
ingredients you have available, different options may, or may not, be suitable.
(There is no point planning to make beef stroganoff, if all you have is chicken).
Planning and preparation are an important part of the process (both in cooking and
in data analysis). Some things you will need to consider are:
• Do you have the correct ingredients in the right amounts?
• What preparation is needed to get the ingredients ready to cook?
• What type of cooking approach will you use (boil, bake, stir-fry)?
• Do you have a picture in your mind of how the end result (e.g., chocolate cake) is
supposed to look?
• How will you tell when it is cooked?
• Once it is cooked, how should you serve it so that it looks appetising?
The same questions apply equally well to the process of analysing your data.
You need to plan your experiment or survey so that it provides the information you
need, in the correct format. You must prepare your data file properly and enter
your data carefully. You should have a clear idea of your research questions and
how you might go about addressing them. You need to know what statistical
techniques are available, what sort of data are suitable and what are not. You must
be able to perform your chosen statistical technique (e.g., t-test) correctly and
interpret the output. Finally, you need to relate this ‘output’ back to your original
research question and know how to present this in your report (or in cooking

terms, should you serve your chocolate cake with cream or ice-cream? or perhaps
some berries and a sprinkle of icing sugar on top?).
Introduction and overview xiii
In both cooking and data analysis, you can’t throw all your ingredients in
together, shove it in the oven (or SPSS, as the case may be) and pray for the best.
Hopefully this book will help you understand the data analysis process a little
better and give you the confidence and skills to be a better ‘cook’.
Structure of this book
This SPSS Survival Manual consists of 21 chapters, covering the research process
from designing a study through to the analysis of the data and presentation of the
results. It is broken into five main parts. Part One ( Getting started) covers the
preliminaries: designing a study, preparing a codebook, and becoming familiar with
SPSS. In Part Two (Preparing the data file) you will be shown how to prepare a data
file, enter your data, and check for errors. Preliminary analyses are covered in Part
Three, which includes chapters on the use of descriptive statistics and graphs; the
manipulation of the data; and the procedures for checking the reliability of scales.
You will also be guided, step by step, through the sometimes difficult task of
choosing which statistical technique is suitable for your data.
In Part Four the major statistical techniques that can be used to explore
relationships are presented (e.g., correlation, partial correlation, multiple
regression factor analysis). These chapters summarise the purpose of each
technique, the underlying assumptions, how to obtain results, how to interpret the
output, and how to present these results in your thesis or report.
Part Five discusses the statistical techniques that can be used to compare
groups. These include t-tests, analysis of variance, multivariate analysis of variance
and analysis of covariance. A chapter on non-parametric techniques is also
included.
Using this book
To use this book effectively as a guide to the use of SPSS you need some basic
computer skills. In the instructions and examples provided throughout the text I
assume that you are already familiar with using a personal computer, particularly
the Windows functions. I have listed below some of the skills you will need. Seek
help if you have difficulty with any of these operations. You will need to be able to:

• use the Windows drop-down menus;
• use the left and right buttons on the mouse;
• use the click and drag technique for highlighting text;
• minimise and maximise windows;
• start and exit programs from the Start menu, or Windows Explorer;
• move between programs that are running simultaneously;
and back again; and
• use Windows Explorer to create folders and to move files between folders.
This book is not designed to ‘stand alone’. It is assumed that you have been
exposed to the fundamentals of statistics and have access to a statistics text. It is
important that you understand some of what goes on ‘below the surface’ when
using SPSS. SPSS is an enormously powerful data analysis package that can handle
very complex statistical procedures. This manual does not attempt to cover all the
different statistical techniques available in the program. Only the most commonly
used statistics are covered. It is designed to get you started and to develop your
confidence in using the program.
Depending on your research questions and your data, it may be necessary to
tackle some of the more complex analyses available in SPSS. There are many good
books available covering the various statistical techniques available with SPSS in
more detail. Read as widely as you can. Browse the shelves in your library, look for
books that explain statistics in a language that you understand (well, at least some
of it anyway!). You might find that some authors explain concepts in a way that
you can understand easily. Collect this material together to form a resource to be
used throughout your statistics classes and your research project. It is also useful
to collect examples of journal articles where statistical analyses are explained and
results are presented. You can use these as models for your final write-up.
The SPSS Survival Manual is suitable for use as both an in-class text, where you
have an instructor taking you through the various aspects of the research process,
and as a self-instruction book for those conducting an individual research project.
If you are teaching yourself, be sure to actually practise using SPSS by analysing the
data that is included on the website accompanying this book (see p. xi for details).
The best way to learn is by actually doing, rather than just reading. ‘Play’ with the
data files from which the examples in the book are taken before you start using
your own data file. This will improve your confidence and also allow you to check
that you are performing the analyses correctly.
• rename, files;open, save, move and close
• that arework with more than one file at a time, and move between files
open;
• use Windows Explorer to copy files from the floppy drive to the hard drive,
xiv SPSSSurvivalManual

Sometimes you may find that the output you obtain is different from that
presented in the book. This is likely to occur if you are using a different version of
SPSS to that used throughout this book (SPSS for Windows Version 10). SPSS is
updated regularly, which is great in terms of improving the program, but it can lead
to confusion for students who find that what is on the screen differs from what is
in the book. Usually the difference is not too dramatic, so stay calm and play
detective. The information may be there but just in a
Introduction and overview xv
Research tips
If you are using this book to guide you through your own research project there are a
few additional tips I would like to recommend.
• Plan your project carefully. Draw on existing theories and research to guide
the design of your project. Know what you are trying to achieve and why.
• Think ahead. Anticipate potential problems and hiccups—every project has
them! Know what statistics you intend to use and use this information to guide
the formulation of data collection materials. Make sure that you will have the
right sort of data to use when you are ready to do your statistical analyses.
• Get organised. Keep careful notes of all relevant research, references etc.
Work out an effective filing system for the mountain of journal articles you will
acquire and, later on, the output from SPSS. It is easy to become disorganised,
overwhelmed and confused.
• Keep good records. When using SPSS to conduct your analyses, keep careful
records of what you do. I recommend to all my students that they buy a spiral
bound exercise book to record every session they spend on SPSS. You should
record the date, new variables you create, all analyses you perform and also
the names of the files where you have saved the SPSS output. If you have a
problem, or something goes horribly wrong with your data file, this
information can be used by your supervisor to help rescue you!
• Stay calm! If this is your first exposure to SPSS and data analysis there may be
times when you feel yourself becoming overwhelmed. Take some deep breaths
and use some positive self-talk. Just take things step by step—give yourself
permission to make mistakes and become confused sometimes. If it all gets too
much, then stop, take a walk and clear your head before you tackle it again.
Most students find SPSS quite easy to use, once they get the hang of it. Like
different form. For information on changes to SPSS for Windows, refer to the
website that accompanies this book (see p. xi for details).

learning any new skill, you just need to get past that first feeling of confusion
and lack of confidence.
• Give yourself plenty of time. The research process, particularly the data entry
and data analysis stages, always takes longer than expected, so allow plenty of
time for this.
• Work with a friend. Make use of other students for emotional and practical
support during the data analysis process. Social support is a great buffer
against stress!
xvi SPSS Survival Manual
There are a number of different topic areas covered throughout this book, from
the initial design of a study, questionnaire construction, basic statistical techniques
(t-tests, correlation), through to advanced statistics ( multivariate analysis of
variance, factor analysis). The References relating to each chapter appear at the
end of the chapter. Further reading and resource material can be found in the
Recommended references at the end of the book.
Download this book’s full version here:
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