Third Edition
This edition first published 2016
© 2016 John Wiley & Sons, Ltd
First Edition published in 1996
Second Edition published in 2002
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Library of Congress Cataloging-in-Publication Data
Names: Greenfield, Tony, editor. | Greener, Sue, editor.
Title: Research methods for postgraduates / edited by Tony Greenfield with
Sue Greener.
Description: Third edition. | Chichester, UK ; Hoboken, NJ : John Wiley &
Sons, 2016. | Includes index.
Identifiers: LCCN 2016011607 (print) | LCCN 2016016287 (ebook) | ISBN
9781118341469 (pbk.) | ISBN 9781118763001 (pdf) | ISBN 9781118762998 (epub)
Subjects: LCSH: Research–Methodology.
Classification: LCC Q180.55.M4 R473 2016 (print) | LCC Q180.55.M4 (ebook) |
DDC 001.4/2–dc23
LC record available at https://lccn.loc.gov/2016011607
A catalogue record for this book is available from the British Library.
ISBN: 9781118341469
Tony Greenfield was born in Chapeltown, South Yorkshire on 26 April 1931 to Geoffrey James Greenfield (1900–1978) and Hilda Aynsley (1903–1976).
Tony worked in a Cumbrian iron mine when he left Bedford School at the age of 17. He later worked in coal mines, a brass tube factory and a copper mine and studied mining engineering at Imperial College London. He received the diploma in journalism from the Regent Street Polytechnic, worked technical journals and on the Sunday Express and Sunday Mirror before turning to technical journalism, in Sheffield, for 10 years. He was an active member of the Sheffield Junior Chamber of Commerce of which he was chairman of the Local Affairs, Business Affairs and Public Speaking committees and editor of The Hub, the chamber's monthly magazine. At the 1963 conference in Tel Aviv of Junior Chamber International, he was acknowledged as the editor of the best junior chamber magazine in the world.
He moved into the steel industry to write technical reports for Operations Research (OR) scientists. There he found satisfaction in solving production problems, and studied OR, mathematics, statistics and computing, leading to an external degree from University College London. He moved into steel research and became head of process computing and statistics. Much of his work was in design and analysis of experiments for which he received his PhD. He co-authored the first interactive statistics package to be written in Fortran. When the laboratories closed, he joined the medical faculty of University of Sheffield where he was statistician to a multi-centre study of cot death. He taught medical statistics to undergraduates, supported post-graduates and medical staff with consultancy. Tony moved to Belfast as professor of medical computing and statistics at Queen's University. Early retirement enabled him to work as a research consultant.
Tony's passion is to persuade all scientists and engineers to write, speak and present their work in language that other people understand well enough to use. And, like W.B. Yeats, he asks scientists to “think like a wise man but communicate in the language of the people”.
Like Isaac Asimov, he is “on fire to explain and doesn't indulge in scholarly depth”. He believes strongly that the economic fortune of Europe depends on the success in the world markets of our manufacturing industries.
“Statisticians and statistical practitioners across Europe know that statistical methods have improved business and industrial peformance – and can do so in the future”, he says. “Our national quality of life will be improved and secured if we can communicate the philosophy, as well as the methods, of statistics to engineers and others in the manufacturing and the service industries. Businessmen and engineers need to understand the benefits of applied probability and statistics; they need to understand how the methods are applied to their own work; they need to be fully converted to a frame of mind that will make them automatically question sources of variability in everything that they do and, without outside prompting, adopt the statistical approach”.
He and others founded ENBIS to stimulate the application of statistical methods to economic and technical development and to business and industry across the whole of Europe. They have created a networking forum for the exchange of ideas between statistical practitioners. He has spread this passion by speaking in many cities across Europe from Tel Aviv, through Turin, Budapest, Ljubljana, Copenhagen, Brussels, Sheffield, Newcastle and London.
“Would you like to produce a third edition?” asked Heather. “Wiley have bought the rights from Hodder. I read the second edition and looked for competition. There is no other book about research methods as good as yours”.
She assured me that I could apply my own style and that she and others at Wiley would help me as much as they could.
Years have passed since the first edition, and I have grown old, so this is my last work for the scientific and technical literature. I have depended entirely on all authors of chapters, for whose patience and understanding I am immensely grateful. They are all erudite and enthusiastic about their own subjects and eager to inspire you, our students, to do first-class research. I hope my own story will also inspire you.
This is a personal story. Perhaps this is the wrong place for a personal story but I want to tell it, as my attempt to inspire you.
“Is statistics a science?” is a hackneyed old question. It discomforts me. The question is needless. It is needless because it is predicated by the assumption that there are many sciences.
We have split science into several separate sciences, but the splits are artificial.
What is my science? I am a scientist. (No splits.)
We do split science into subject areas for pedagogical convenience in schools and universities. I do remember most of the chemistry, physics and biology I learned at school 70 years ago. I could not claim to be a chemist, physicist or biologist. But I would not say, as I was once shocked to hear a statistician say, “I cannot discuss the design of an aerofoil because I am not an aeronautical engineer; I am a statistician”.
Statistics is a part of science, but it is not ‘a science’; it is a subject area within science just as is chemistry. And it has no discrete boundary, as neither does chemistry.
Statistics provides method to science:
Do you ever notice something; describe it; ask yourself, “What is it? Why is it? Where it it? Is it useful to me or to anybody else? Does it have any relationship to anything else?” Then you have the makings of a scientist.
But, and this is where the usefulness of statistics arrives, do you then invent a working assumption, called a hypothesis, that is consistent with what you have observed? If you do, can you then use the hypothesis to make predictions?
Now, you must see clearly that statistics is an essential tool of science. You can test your predictions by experiments or further observations and modify the hypothesis in the light of your results. The scientific method insists that you keep revising your hypothesis and experimenting until you can detect no discrepancies between your hypothesis and your observations. You may then, correctly in the scientific realm, tell the world that you have a theory that may explain a class of phenomena.
A theory, by my description and by dictionary definition, is a framework within which observations are explained and predictions are made.
I once proposed a curriculum approach to representation of statistics as the cement for binding science's subject areas. This was in a paper, The polymath consultant, at the first meeting of ICOTS (International Conference on Teaching Statistics). The Times newspaper published a short version of it. The UK secretary of state for education, Keith Joseph, was interested enough to invite me to discuss it, and he encouraged me to promote the idea in universities. Nobody else took any notice. Yet I still believe that there was an idea that could be developed as part of our search for the future of data analysis. We must teach that statistical methods are just as part of, and just as applicable, in social studies as they are in physics and chemistry; and that they are as useful in linguistics, history and geography as much as they are in engineering and marketing.
Collections of worked practical cases, such as those by Cox and Snell (1981), must help and we need more of them. A recent book (Greenfield and Metcalfe 2007) aims at this with more than 50 worked cases about school absence, metro noise levels, water fluoridation, diamond prospecting, wine tasting, compulsive gambling, prosthetic heart valves and many more.
Evidence is the life-blood of science and scepticism is its spark of life. Data analysis is the flux of evidence. We should continue to ensure that all scientists, in all subject areas, and these include you, perceive it as such. Always you must be sceptical about any assertion that has no evidential support. Nullius in verba.
Frances Ashcroft, a truly great scientist of this, the twenty-first century, tells us in a recent book how her own research excited her.
I discovered that the KATP channel sits in the membrane that envelops the beta-cell and regulates its electrical activity and thereby insulin release.… The breakthrough came late at night when I was working alone.… I was ecstatic. I was dancing in the air, shot high into the sky on the rocket of excitement with the stars exploding in vivid colours all around me. Even recalling that moment sends excitement fizzing through my veins, and puts a smile on my face.
There is nothing — nothing at all — that compares to the exhilaration of discovery, of being the first person on the planet to see something new and understand what it means. It comes all too rarely to a scientist, perhaps just once in a lifetime, and usually requires years of hard grind to get there. But the delight of discovery is truly magical, a life-transforming event that keeps you at the bench even when times are tough. It makes science an addictive pursuit.
That night I felt like stout Cortez, silent upon his peak in Darien, gazing out across not the Pacific Ocean, but a landscape of the mind. It was crystal clear where my mental journey must take me, what experiments were needed and what the implications were.
Next morning, all certainty swept away, I felt sure my beautiful result was merely a mistake. There was only one way to find out. Repeat the experiment — again and again and again. That is the daily drudgery of a scientific life: it is very far from the ecstasy of discovery.
The Spark of Life Electricity in the Human Body
Frances Ashcroft
Such reporting inspired me to read the rest of the book even though, in her last paragraph, she warns that all of us, including you, cannot expect winning without drudgery. Thomas Edison expressed this well:
Genius is one percent inspiration, ninety-nine percent perspiration.
Spoken statement (c. 1903); published in Harper's Monthly (September 1932)
Many writers in the past have felt the same elation as Frances Ashcroft. John Keats, for example, recorded that feeling:
Then felt I like some watcher of the skies
When a new planet swims into his ken;
Or like stout Cortez when with eagle eyes
He star'd at the Pacific — and all his men
Look'd at each other with a wild surmise —
Silent, upon a peak in Darien.
John Keats
Mary Shelley told us how Doctor Frankenstein's feeling went further from the beauty of scientific achievement to disgust at what he had done.
The different accidents of life are not so changeable as the feelings of human nature. I had worked hard for nearly two years, for the sole purpose of infusing life into an inanimate body. For this I had deprived myself of rest and health. I had desired it with an ardour that far exceeded moderation; but now that I had finished, the beauty of the dream vanished, and breathless horror and disgust filled my heart.
Frankenstein (chapter 5) Mary Wolstencroft Shelley
If, as a scientist, you can keep powering the bellows that inflame your spark of inspiration into a bright light of scientific achievement, scientists will acknowledge that you are one of them. But, first, you must be sure that you believe you are a scientist. You must have started somewhere, sometime. Here is how and when and where I started.
“Tell Father that lunch is ready,” said Mother. “He's in the garage”.
I loved Sunday lunch when I was six, especially when it was roast beef, Yorkshire pudding, dark green cabbage and rich gravy. I went to the garage to summon Father to the table where he would display his knife sharpening and carving skills.
He was on the floor, asleep, and his face had a bluish greenish tinge.
I ran to Mother. She quickly opened the doors and windows and called an ambulance. She dragged him onto the lawn and pumped his chest. He breathed and his face turned grey. An ambulance arrived. The men put a mask over his face. It was connected by a rubber tube to a cylinder of oxygen. His face turned pink. The ambulance drove away and we had lunch, a little late.
Carbon black is an amorphous carbon with a high surface-area-to-volume ratio. It is used as a pigment and reinforcement in rubber and plastic products. It also helps to conduct heat away from the tread and belt area of the tyre, reducing thermal damage and increasing tyre life. It is very expensive. It was even more expensive when I was six and Father thought he could make a lot of money by producing it from cheap by-products, usually discarded, from coal distillation or coke making. One of these was naphtha and, as a chemical engineer, he knew where he could get as much as he wanted very cheap. In those days, the Americans made most of the world's carbon black from natural gas and it cost about £5000 a ton (imperial spelling): a lot, especially if you convert that into today's money. Nowadays, with many more sources of materials and more efficient production, it is worth about £500 a tonne (note the SI spelling).
Father explained as much of this to me as I could understand and he showed me his experimental machine. So far as I can remember, nearly 60 years later, it comprised a rotating drum with cooling water circulating through it. There was a row of tiny jets through which he pumped naphtha that burned, with only partial combustion, so that carbon black deposited on the cold drum surface. Naphtha is a crude mix of oils that drained out of the bottoms of coke ovens where it was used by burning to heat the ovens.
I learned, when I was six, that Father was a scientist, an engineer and an experimentalist. But his research had its perils, including the possibility of carbon monoxide poisoning.
Father explained many things to me over the years.
He drove to a coke oven plant in Scunthorpe when I was 11. I went too but, in case I was bored, I carried a Just William book (by Richmal Compton). At the ovens, we sat all night measuring things as they happened. Father told me, “This is called ‘dynamic measuring’ ”. I watched, fascinated, as ink flowed onto rotating graphs. In the morning, Father analysed the data and advised the works manager on how to improve his benzole production. Benzole (a mix of benzene and toluene) had been seen, by coke-makers, as a waste by-product. In 1942, it was an essential fuel for the Spitfire.
This was science in the raw and I was excited, never bored.
I was 15 when I bought an ancient motorbike that wouldn't go. Father commented that I would be a competent mechanic and understand internal combustion engines by the time I was allowed to drive it. A year later I had fixed it but petrol was rationed. I decided to make my own. I had fitted the bike with acetylene lights instead of electric lights. A local garage gave me a drum of (calcium) carbide that they no longer needed. Water drips onto carbide to produce acetylene which, at one time, was used for lighting. I also knew that acetylene (C2H2) could be polymerised to benzene (C6H6) by contact with red-hot iron or most alloys in which iron is the dominant component, at about 700 oC. I wound an electric fire element round the gap between two silicon tubes which I sealed into a large silicon jar connected by a rubber tube to an acetylene generator more than a metre from the jar. I intended to send acetylene into the jar; heat from the fire element would draw the gas up and then down again until benzene appeared. When, eventually, I had made a litre of benzene, I would experiment with mixed proportions of paraffin (not rationed) to discover the best mix to drive my motorbike.
Grandpa's brick garage was integral to the house. Father's was wooden and that is where I had my benzene plant. The power switch was by the door. I started the acetylene generator and let it run for about 10 minutes to expunge all air from the jar. Then I switched on the power; and watched.
Two minutes later, I saw: drip…drip…drip…from the silicon tubes.
Frances Ashcroft expressed my feelings later: “I was ecstatic. I was dancing in the air, shot high into the sky on the rocket of excitement with the stars exploding in vivid colours all around me.”
I watched, enslaved by the sight of my success, but for only a few seconds.
A crack of thunder, a great white light, and the apparatus went through the roof and fell in the garden.
I studied the hole in the roof and caught the next bus to Worthing. I arrived home late at night. Father was still up. I said nothing. “Are you afraid of me?” he asked. “Yes”. “No need”, he said. “I am proud of you”.
Weeks later, my physics master said Father had told him the story and he, too, was proud of me. “You will be a good experimentalist”, he predicted, “but you will always be the servant of others unless you learn about patents”.
When that teacher demonstrated the Michelson–Morley experiment, and said it proved that ether did not exist, I said perhaps it did but it may have properties that were hidden from the experiment. “You have a curious mind, Greenfield”, he said. Father said I had a hypothesis as good as any, and he encouraged me to design an experiment to test it.
Red shift is generally accepted as evidence of universal expansion. Father again encouraged me to design an experiment to test an alternative hypothesis. Although we borrowed a quarry to set up an experiment, the apparatus we designed and built was not good enough.
At 18, I had my first provisional patent for a photographic colour method using the five oxides of vanadium. Kodak were interested but couldn't improve on my colours, the worst of which gave brown instead of green.
Thirty years later:
“I like your style”, said the visiting professor.
His compliment came towards the end of the first course I gave on research methods to the medical faculty of Queen's University, Belfast.
The course arose from my experiences in steel research, in Sheffield University and in Queen's University. In all of these I had found a shocking inability among scientific researchers to write and to speak clearly about their research. Scientific books and papers are so mysterious, so arcane, so bewildering, that scientists can understand only those of their own speciality. They are obscure to others.
I had also been shocked in all these places by the lack of appreciation of statistical and other research methods. A short, sharp course was needed. The faculty dean agreed and encouraged me to run such a course, which I did every year for five years. Students ranged from new medical graduates to senior consultants and professors. Teachers included the dean, a librarian, computer staff, statisticians, professors of clinical psychology, epidemiology and chemical pathology, and the chairman of the research ethics committee.
“I didn't know I had a style”, I replied. “What is it?”
“You always look as if you don't know what you will say next”, the visiting professor told me.
I knew that was true. I always watch students' faces and look into their eyes to be sure that they understand what I am saying. That is an essence of teaching, but it is hard in a lecture hall with 150 students; it is easy in a classroom with no more than 30, which I had.
I can't see the eyes of students when they read a text book, but I can try to write in a style that will grab and keep their attention. Contributors to earlier editions of this book agreed. Unfortunately, the publisher's editors disagreed and, in my view, ruined the style of the second edition. They made changes to the text that were far beyond acceptable editing. They were changes with which I did not agree: changes that affected my style and the styles of other authors. They refused to repair the damage, and eventually I surrendered.
Felix Grant, author of one chapter, wrote to me: “Watching the progress of this whole spectacle has been an education. I shall never look at Hodder or their imprints in the same way again, not only as a writer but as a professional and as an educational book buyer. I admire your tenacity and integrity; I hope I have the same level of commitment to what matters, if it should come to that. I am, after a break of two decades, currently starting on the long process of steering a book of my own through ‘another publisher’. If your experience with Hodder turns out to be typical of changes in publishing's attitudes to quality and verity over that time, I shall be very disappointed”.
I apologise to Felix for my surrender, and to other authors and readers who feel the same. Felix wrote again for this edition. I wish he could see it. Sadly, he died a few months before we went to press.
Wiley have promised no such desecration. They like and enjoy the style that I have encouraged all authors to adopt. Their editors (Debbie Cox and Heather Kay) agree with John Gribbin who wrote, in his New Scientist review of the first edition, “The most useful book any new postgraduate could ever buy”.
Debbie, Heather and Richard Davies have supported this project wonderfully. For myself, and for all the authors and readers, I thank them.
But some authors know that during the course of this work I have developed Parkinson's disease. This delayed production for four years. Heather recruited two angels to help. One is Sue Greener (see chapters 2, 12, 15, 16, 37, and 38) a delightful and positive writer and editor. The other is Liz, my wife, who eagerly follows Heather's instructions to keep me going and keeps in touch with Sue.
Now we have the best edition with revised chapters, new chapters and new writers. You will enjoy reading this book so much that you won't want to put it down. You will start with a journey through the general research scene.… This is where the hard work begins: collect data, analyse and interpret data, and write and publish articles, news items, technical reports and a thesis that you must present to your examiners.
You, the researcher, the problem solver, are responsible to a manager: in a company, a university or a government department. You must report results so that the manager can understand them enough to make decisions. Research does not end with design and analysis. You must interpret and communicate the results. Unless you can describe and explain your results to people who do not share your analytic skills, your results will be worthless. Read the book.
I have no data yet. It is a capital mistake to theorise before one has data. Insensibly one begins to twist fact to suit theories, instead of theories to suit facts.
Sherlock Holmes
A Scandal in Bohemia
Tony Greenfield