Research Methods and Statistics in Psychology

714 Pages·2009·5.68 MB·English

by  Hugh Coolican

5th Edition
Research Methods
Statistics
and in
Psychology
Hugh Coolican
RMSP Prelims pages 24/2/09 8:14 am Page i
5th Edition
Research Methods
Statistics
and in
Psychology
Hugh Coolican
RMSP Prelims pages 24/2/09 8:14 am Page ii
Acknowledgements
To Alison Wadeley for a very thoughtful and useful review of the fourth edition. To my students
whose assignments always show me what’s needed and on whom I try out some of the ideas. To
tutors and enquirers who have offered suggestions or pointed out errors. A special thanks to all
staff involved at Hodder Education but especially Tamsin Smith, Bianca Knights, and to Susan
Dunsmore for some painstaking copy-editing.
Every effort has been made to trace and acknowledge the owners of copyright. The publishers will be glad to make suitable
arrangements with any copyright holders whom it has not been possible to contact.
First published in Great Britain in 2009
by Hodder Education

Published 2013 by Routledge
2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN
711 Third Avenue, New York, NY, 10017, USA

Routledge is an imprint of the Taylor & Francis Group, an informa business

Copyright © 2009, Hugh Coolican

All rights reserved. No part of this book may be reprinted or reproduced or
utilised in any form or by any electronic, mechanical, or other means, now
known or hereafter invented, including photocopying and recording, or in
any information storage or retrieval system, without permission in writing
from the publishers.

The advice and information in this book are believed to be true and
accurate at the date of going to press, but neither the authors nor the publisher
can accept any legal responsibility or liability for any errors or omissions.

British Library Cataloguing in Publication Data
A catalogue record for this title is available from the British Library

Library of Congress Cataloging-in-Publication Data
A catalog record for this book is available from the Library of Congress

ISBN 13: 978-0-340-98344-7 (pbk)

Typeset in 10/13pt StempelSchneidler by Dorchester Typesetting Group Ltd
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Dedication
To Rama, Kiran and Jeevan for your understanding
and support during yet another ‘book year’.
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Contents
Preface viii
1 Psychology,science and research 1
Why psychology and science? Science – not a subject but a way of thinking;So what
is this scientific method then? Asking why? Generating theories for laws;The
hypothetico-deductive method;How psychologists actually do scientific research;
What are the main features of a psychological investigation? Qualitative data and
qualitative approaches
2 Measuring people – variables,samples and the qualitative critique 28
Variables;Operational definitions of psychological constructs;Reliability and validity;
Samples;Probability based sampling methods;Non-probability based sampling
methods;Purposive sampling;Introducing the qualitative/quantitative debate
3 Experiments and experimental designs in psychology 56
The role of experiments in gathering evidence – demonstrating cause and effect;
Alternative explanations;Features of the true experiment;Simple experimental
designs (Independent samples design,Repeated measures design,Matched-pairs
design);Single participant or small n design
4 Validity in psychological research 81
The interpretation of experiments;Sources of variance on the experiment;Validity in
experiments and other research designs;Types of validity (Statistical conclusion;
Internal;Construct); Tackling confounds in psychological research;Expectancy;External
validity;Meta-analysis
5 Quasi-experiments and non-experiments 106
The field and the laboratory;True experiments and field experiments;The quasi-
experiment;Non-experimental research;Control and validity in the laboratory and in
the field
6 Observational methods – watching and being with people 123
Observation in general;Observation as a technique or as an overall design;
Controlled observation;Qualitative non-participant observation;Role-play and
simulation;The diary method;Participant observation;Case studies;Indirect
observation
7 Interview methods – asking people direct questions 150
Introduction – Self-report methods;Structured interviews;Effects of interpersonal
variables in interviews;Types of interview;Semi-structured or open interviewing –
gathering qualitative data;Surveys
8 Psychological tests and measurement scales 172
Introduction;Measurement vs.information gathering;scales,tests,inventories and
questionnaires;Open and closed questions;Attitude scales;Central issues in the use of
psychological scales;Scale items – what to avoid in statement construction;Projective
tests;Intelligence and personality tests;Reliability,validity and standardisation
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9 Comparison studies – cross-sectional,longitudinal and cross-cultural studies 206
What are comparison studies? Cross-sectional studies;Longitudinal studies;Evaluation of
longitudinal and cross-sectional studies;Cross-cultural studies
10 Qualitative approaches in psychology 222
Psychology and the positivist paradigm;The problem with quantification in psychological
research;Qualitative data gathering (Grounded theory,Interpretive phenomenological
analysis,Discourse analysis,Thematic analysis,Ethnography,Action research) Participative
and collaborative research;Memories as narratives;A feminist perspective;
Contemporary qualitative methods
11 Statistics – organising the data 247
Measuring things;Different levels of measurement;Summarising data;Measures of central
tendency;Measures of dispersion;Population parameters,sample statistics and sampling
error;Using SPSS to calculate statistics;Appendix – Statistical notation and symbols
12 Graphical representation of data 287
Graphs in general;The bar chart;Line charts;The histogram;Exploratory data analysis;
Using SPSS to produce your charts
13 Frequencies and distributions 305
Dealing with larger data sets;Percentiles,deciles and quartiles;The normal distribution;z
scores;Standardisation of psychological measurements;Sampling distributions;Confidence
intervals;Skewed distributions;Kurtosis
14 Significance testing – was it a real effect? 322
Significance decisions;The null and alternative hypotheses;Probability;Rejecting the null
hypothesis;The standard level of significance;Critical values;Significance testing – the basic
model;Rejection regions;Frequency distributions and probability distributions;Type I and
type II errors;The question of power and effect size;Significance ‘levels’;Directional and
non-directional hypotheses – one and two tailed tests
15 Testing for differences between two samples 350
Tests of difference between two conditions or groups (Parametric tests:the t test for
related data;the t test for unrelated data;the single sample t test) Data assumptions for t
tests;Non-parametric tests of difference (Wilcoxon’s T,Mann-Whitney U,The binomial
sign test);SPSS procedures of two condition difference tests;Effect size and power
16 Tests for categorical variables and frequency tables 397
Tests on two-way frequency tables;Unrelated data – the Chi-square test of association;
The 2 x 2 chi-square;More complex chi-square (r x c designs);The ‘goodness of fit’test;
SPSS procedure for conducting a r x c chi-square test;Multi-way frequency tables and
loglinear analysis;Conducting a three-way frequency analysis in SPSS
17 Correlation 428
Simple correlation;Measurement of a correlation;Correlation coefficients (Pearson
product-moment,Spearman’s rho);Significance and correlation coefficients;Variance
estimates;SPSS procedures for correlation;What you can’t assume with a correlation;
Categorical variables;Common uses of correlation in psychology;Regression and multiple
regression;Multiple predictions;Partial and semi-partial correlation;Regression
coefficients;Effect size and power;Conducting a regression analysis in SPSS
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18 Multi-level analysis – differences between more than two conditions 475
More complex tests;One-way ANOVA – unrelated designs;The F ratio statistic;Effect
size;A priori and post hoc comparisons;Estimating power in one-way ANOVA;Non-
parametric ANOVA equivalent – Kruskal–Wallis (and the Jonckheere trend test);
MANOVA;ANCOVA;SPSS procedures for one-way ANOVA;Kruskal-Wallis in SPSS
19 Multi-factorial designs 501
Using two or more independent variables;Central features (interaction effects,main
effects,simple effects);Effect sizes and power;Three-way ANOVA calculation;SPSS
procedures for two-way between groups ANOVA
20 ANOVA for repeated measures designs 518
Related designs (rationale for one-way repeated measures ANOVA);Between subjects
and between conditions variation;Data assumptions for repeated measures ANOVA;
Two-way related design;ANOVA mixed design – one repeated measure and one
unrelated factor;More complex ANOVA designs;Effect size and power;A non-
parametric equivalent – the Friedman test for correlated samples;SPSS procedures for
repeated measures ANOVA and Friedman
21 Choosing a significance test for your data (and internet resources) 540
Choosing an appropriate test;Tests for two samples;Tests for more than two samples;
Computers and the Internet
22 Analysing qualitative data 554
Quantitative analysis of qualitative data;Qualitative content analysis;Qualitative analysis of
qualitative data;Doing qualitative research;Considerations for a qualitative project;Data
analysis;Procedures in major approaches (grounded theory,interpretive
phenomenological analysis,discourse analysis);Writing up the report;Reliability and
validity – how are qualitative studies evaluated?
23 Ethical issues in psychological research 585
Introduction;Publication and access to data;The conduct of research with human
participants;Research with animals – case for and against;conclusion
24 Planning your practical and writing up your report 603
Planning your practical project (the overall aim,the design,the samples,the material,the
procedure,ethics);Writing your practical report;Comments on a student practical report
(a better report of the same practical)
Appendix to Chapter 22 641
Appendix 650
References 671
Index 689
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Preface
This book is for anyone starting out on a psychology course which contains a fair amount of
hands-on practical research training and the writing up of psychological reports. It will be most
useful for those studying for a psychology degree but will also serve students on Masters courses in
psychology (where methods knowledge may have become a little rusty), on other social sciences
courses, on nursing degrees and in several other related disciplines. The common factor is the need
to understand how researchers gather data in a fair and unbiased manner and how they analyse
and interpret those data. A feature that I’m sure all such readers would be pleased to find is a
friendly common-sense approach that uses clear concrete examples to explain otherwise abstract
and sometimes complex notions. In the past this book has been praised for doing just that and I
truly hope it continues to do so.
A basic premise of the book has always been that people start out on research methods courses
with many of the basic principles already acquired through their experience of everyday life. To
some extent the job of tutors and writers is to harness those concepts and to formalise and then
elaborate upon them. Before you do psychology you probably know just what a fair experiment
would be, what an average is, what it means when people deviate a lot from an average and even
the fundamentals of statistical significance– you can probably tell intuitively when samples of girls’
and boys’ reading scores differ by an amount that cannot be explained just by chance variation.
Hence you are not really starting out on something you know little about no matter how frightened
you may be of numbers and science.
One of the bonuses of studying research methods and statistics is that you greatly enhance what
Neil Postman (1987) referred to as your personal ‘crap detection’ system, to put it rather crudely.
That is, a study of methods and statistics at the very least and done properly will enable your
ability to spot gross errors in the statistical arguments of advertisers, politicians and charlatans who
try to use numbers or ‘findings’ to bamboozle you. There are several examples of such poor
methods or data massaging in the book and hopefully you will later be able to argue ‘Ah but,…..’
at dinner parties and become everybody’s best friend as you point out the flaws in the assumptions
people make from ‘findings’ that have made the news.
Many people start psychology courses with a very strong fear of the statistics that may be
involved. This is understandable if, for you, the world of numbers has always been something of a
no-go area. However, statistics is one of the easiest areas of maths (it must be, both my children
said so, even the one for whom maths was a nightmare).
You should not have to do a lot of by-hand calculating, unless your tutors are sadists! Psychology is
not about (re-)learning to do sums; it’s about using statistical tools to summarise data and to show
people that we have found a relationship between the data that supports a particular view or
theory about how people work. Where you do have to calculate, be assured that the actual
calculation steps for most procedures neverextend beyond the basic capability of the average 11
year old, and can all be done on a £2 calculator.
In this fifth edition (I can’t believe this book started 20 years ago!) there have been several changes.
Exercises have been moved so that they follow each substantive piece of work rather than
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appearing only at the end of a chapter. There are an increased number of stop and think exercises
now in boxes called ‘Pause for thought’. Instructions for SPSS now cover the latest edition (v.16) as
well as the last few previous versions for the most part. In the statistics sections the way to report
each statistical test, introduced in the fourth edition, has been augmented in each case by the way
to report effect size and confidence limits where appropriate.
Qualitative methods, as ever, are integrated into general chapters (e.g. interviewing, observation
and the quantitative–qualitative debate in Chapter 2) and two specialist chapters. The first edition
was almost certainly the first general methods text in the UK to pay specific attention to qualitative
methods. These have been updated again and there is a new appearance for narrative analysis and
an expanded section on thematic analysis. The example qualitative article has been replaced by one
that much more clearly follows a grounded theory approach. For qualitative methods in particular,
but also in general, there are far more website addresses to consult for further information and
resources. There are several attempts to tackle ‘psychology myths’ such as what the Hawthorne
studies really showed, how Zimbardo biased his famous study and, more substantially, a debate on
the much misused term ‘ecological validity’ which is extended on the companion website,
www.routledge.com/cw/coolican .
This companion website is a major new technology addition and I have used it to post several
more extended debates and detailed information that could not have appeared in the book itself for
reasons of size. I hope to continue to add to this site, including more exercises, more debates and
further links to useful resources as they appear.
I encourage feedback, queries and, yes, people just telling me I’m wrong about something – how
else would we learn? This time around you will be able to e-mail me your queries using the
website and I will attempt to provide a clear response. Finally I’d like to repeat something from the
fourth edition preface. While you toil away, writing those inevitable reports, just keep thinking that
none of the truly fascinating ideas about human behaviour and experience and none of the
wonderful insights about ourselves that can be gained on a short psychology course would be
possible without someone (many committed people in fact) doing exactly as you are doing!
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