Interpreting Quantitative Data with SPSS

337 Pages·2002·2.97 MB·English

by  Rachad Antonius

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Interpreting Quantitative Data with SPSS
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Interpreting Quantitative Data
with SPSS
Rachad Antonius
SAGE Publications
London • Thousand Oaks • New Delhi
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© Rachad Antonius 2003
First published 2003
Apart from any fair dealing for the purposes of research or
private study, or criticism or review, as permitted under
the Copyright, Designs and Patents Act, 1988, this publication
may be reproduced, stored or transmitted in any form, or by
any means, only with the prior permission in writing of the
publishers, or in the case of reprographic reproduction, in
accordance with the terms of licences issued by the Copyright
Licensing Agency. Inquiries concerning reproduction outside
those terms should be sent to the publishers.
SAGE Publications Ltd
6 Bonhill Street
London EC2A 4PU
SAGE Publications Inc
2455 Teller Road
Thousand Oaks, California 91320
SAGE Publications India Pvt Ltd
32, M-Block Market
Greater Kailash - I
New Delhi 110 048
British Library Cataloguing in Publication data
A catalogue record for this book is available from
the British Library
ISBN 0 7619 7398 2
ISBN 0 7619 7399 0 (pbk)
Library of Congress Control Number: 2002 102 782
Typeset by C&M Digital (P) Ltd., Chennai, India
Printed in Great Britain by TJ International Ltd, Padstow, Cornwall
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CONTENTS
ACKNOWLEDGMENTS ix
FOREWORD TO THE STUDENT xi
FOREWORD TO THE INSTRUCTOR xvii
1 THE BASIC LANGUAGE OF STATISTICS 1
Introduction: Social Sciences and Quantitative Methods 1
Data Files 2
The Discipline of Statistics 6
Populations, Samples, and Units 7
Descriptive Statistics 9
Inferential Statistics 9
Variables and Measurement 10
Importance of the Level of Measurement 16
Concepts, Dimensions, and Indicators 17
Summary 18
Keywords 19
Suggestions for Further Reading 19
Exercises 20
2 THE RESEARCH PROCESS 22
Main Steps in Social Research 23
Summary 31
Keywords 31
Suggestions for Further Reading 31
Exercises 33
3 UNIVARIATE DESCRIPTIVE STATISTICS 34
Measures of Central Tendency 36
Measures of Dispersion 46
Measures of Position 51
Other Measures 52
Graphical Representation of the Distribution of Data 53
The General Shape of a Distribution 66
Methodological Issues 67
Summary 69
Keywords 70
Suggestions for Further Reading 71
Exercises 71
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vi CONTENTS
4 WRITING A DESCRIPTIVE SUMMARY 78
How to Write a Descriptive Report 78
Summary 95
Keywords 96
Suggestions for Further Reading 96
Exercises 96
5 NORMAL DISTRIBUTIONS 97
Properties of Normal Distributions 98
Using the Table of Areas Under the Normal Curve 100
Numerical Examples 103
Summary 105
Keywords 106
Suggestions for Further Reading 106
Exercises 106
6 SAMPLING DESIGNS 107
Types of Samples 108
Errors of Measurement 117
Summary 118
Keywords 119
Suggestions for Further Reading 119
Exercises 119
7 DATABASES ON SOCIAL STATISTICS 122
Illustration of a Data Search on Selected Sites 126
Printed Reports of Statistics Canada (or StatCan) 131
CD-ROMs and Disks 135
Online Data at StatCan 136
Keywords 140
Suggestions for Further Reading 140
Exercises 140
8 STATISTICAL ASSOCIATION 142
The Case of Two Quantitative Variables 145
The Case of Two Qualitative Variables 148
The Case of One Quantitative and One
Qualitative Variable 153
Ordinal Variables 153
Statistical Association as a Qualitative Relationship 154
Summary and Conclusions 156
Keywords 158
Suggestions for Further Reading 158
Exercises 158
9 INFERENTIAL STATISTICS: ESTIMATION 161
Inferential Statistics 161
The Logic of Estimation: Proportions and Percentages 163
Estimation of a Percentage: The Calculations 165
Estimation of a Mean 168
Estimation of a Mean: The Calculations 169
Effect of the Sample Size on the Margin of Error 170
Calculation of the Sample Size Needed in a Survey 171
Summary and Conclusions 172
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Keywords 173
Suggestions for Further Reading 173
Exercises 174
10 INFERENTIAL STATISTICS: HYPOTHESIS TESTING 177
Sampling Distributions 179
The Logic of Hypothesis Testing 180
The Detailed Procedure for Hypothesis Testing 182
Understanding the Probabilities of Error 184
The Various Forms of the Alternative Hypothesis 185
Hypothesis Testing When σ is Unknown 188
Hypothesis Testing with Two Independent Samples 189
Hypothesis Testing in Statistical Software 190
t-Tests 190
Summary and Conclusions 191
Keywords 191
Suggestions for Further Reading 192
Exercises 192
SYNTHESIS: ANALYZING A TOPIC IN A DATA FILE 195
The Data File Itself 195
The Topic and the Questions 195
The Analysis 196
REVIEW QUESTIONS 202
LAB 1: GETTING STARTED WITH SPSS 206
LAB 2: WORKING WITH A WORD PROCESSOR 213
LAB 3: EXPLORING DESCRIPTIVE STATISTICS 216
LAB 4: RECODING; THE HELP MENU 226
LAB 5: CHARTS IN SPSS 235
LAB 6: MORE ON DESCRIPTIVE STATISTICS 239
LAB 7: RANDOM SAMPLING 242
LAB 8: ACCESSING DATABASES ON THE INTERNET 245
LAB 9: CREATING A DATA FILE 248
LAB 10: CROSS-TABULATIONS (TWO-WAY TABLES) 256
LAB 11: COMPARING THE MEANS OF
VARIOUS SUBGROUPS 261
LAB 12: CORRELATION AND REGRESSION 266
LAB 13: CONFIDENCE INTERVALS 272
LAB 14: t-TESTS 277
APPENDIX 1 AREAS UNDER THE NORMAL CURVE 284
APPENDIX 2 TABLE OF RANDOM NUMBERS 285
GLOSSARY OF STATISTICAL TERMS 286
GENERAL BIBLIOGRAPHY 296
INDEX 299
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ACKNOWLEDGMENTS
A number of contingencies have presided over the coming about of this book … and
a number of people have played a role in its birth. I would like to acknowledge their
input here.
First of all, there was Louise Corriveau, who first encouraged me to work on a
manual of quantitative methodology for the social sciences. She introduced me to a
statistician, the late Robert Trudel, and together we wrote Méthodes quantitatives
appliquées aux sciences humaines. Our long and elaborated discussions on every
aspect of the book,both from the point of view of statistics and from the point of view
of pedagogy,helped shape my views of how that subject matter ought to be taught. I
should point out the role played then by Mr. Charles Dufresne,whose advice on the
form,content and organization of that book was an extremely formative experience.
As computers were becoming available for our classes,we started using software
packages to teach this course. After experimenting with several packages,the admin-
istration and instructors of the course opted for SPSS. We had manuals to teach
SPSS, but we did not have a manual to teach quantitative methods for the social
sciences with the help of a package such as SPSS.
I thus wrote a series of class notes in quantitative methodology using SPSS. The
focus was on methodology,and SPSS was a tool,not an end in itself. With the com-
ments of my students and my colleagues at Champlain College – St-Lambert,these
notes gradually evolved into an experimental manuscript. This book is the result of
these efforts.
I would like to thank my colleagues – both in the Mathematics department and in
the Methodology module – for letting me teach the course,and for testing the man-
ual in their classes. The administration at Champlain was quite supportive, and
accommodated my needs in terms of teaching and of granting (unpaid …) leaves of
absence when that was required. They also provided numerous signs of encourage-
ment and appreciation of this work.
As any author knows,writing a book puts a lot of stress on the daily organization
of family life. I would like to thank my spouse,Y.G., and my children, Marc and
Gabriel,for putting up with my constant preoccupation with statistics and method-
ology during moments when I should have been available to interact with them.
Finally, I would like to thank all the staff at SAGE and Keyword Publishing
Services for their professional editing job.
Rachad Antonius
Montreal,May 20,2002