Statistics in Nutrition and Dietetics. Michael Nelson

prepared brief teaching notes. These outline the approach taken to teach the concepts set out in the textbook. I used traditional lecturing coupled with in‐class work, practical exercises, homework, and research protocol development. My current practice is to avoid exams for any of this material. Exams and formal tests tend to distract students from revision of study materials more central to their course. Some students get completely tied up in knots about learning stats, and they fret about not passing the exam, ultimately to their academic disadvantage.

      PowerPoint slide sets

      The principal aid for tutors and lecturers is slide sets in PowerPoint. These save hours of preparation, provide consistent format of presentation, and build on approaches that have worked well with literally thousands of students that have taken these courses. When using the slides outside the context of teaching based on the text book, please ensure that you cite the source of the material.

      SPSS data, syntax, and output files

      A complete set of SPSS files for the examples and exercises in the text book is provided.

      Learning resources

      The page on Learning Resources includes website links and reviews of the strengths of a number of sites that I like and find especially helpful.

      Unsurprisingly, there is a wealth of websites that support learning about statistics. Some focus on the basics. These are mainly notes from University courses that have been made available to students online. Some are good, some are not so good. Many go beyond the basics presented in this text book. Diligent searching by the student (or tutor) will no doubt unearth useful material. This will be equivalent to perusing the reading that I outline in the Introduction to Chapter 1.

      Flow Charts are useful to find the statistical test that best fits the data. Appendix A10 in this book shows one. There are more online. Two that I like are described in more detail on the Learning Resources page. I have also included links to sites for determining Power and sample size.

      Finally, guidance on the use of Excel and SPSS in statistics is very helpful. There are many sites that offer support, but my favourites are listed on the Learning Resources page.

      Note

      1 1 SPSS stands for ‘Statistical Package for the Social Sciences’. It was developed at Stamford University in California, and the first manual was authored by Norman Nie, Dale Bent, and Hadlai Hull in 1970. The package was bought in 2009 by IBM. The worked examples and syntax in this book are based on Version 24 (2016). It has come a long way since its first incarnation, in terms of ease of use, error trapping, and output. Be grateful.

      Acknowledgements

      I would like to thank the hundreds of students who attended my classes on research methods and statistics. They gave me valuable feedback on what worked and what didn’t in the teaching sessions, the notes, and exercises. Irja Haapala and Peter Emery at King's College London took over the reins when I was working on other projects and made helpful contributions to the notes and slides. Charles Zaiontz at Real Statistics kindly helped with the Wilcoxon U table, and Ellen Marshall at Sheffield Hallam University very helpfully made available the data on diet for the two‐way analysis of variance. Mary Hickson at the University of Plymouth made helpful comments on the text. Mary Hickson, Sarah Berry, and Wendy Hall at King's College London, and Charlotte Evans at the University of Leeds kindly made data sets available. Thanks to the many colleagues who said, ‘You should turn the notes into a book!’ Stephanie, Rob, Tom, Cherie, and Cora all gave me great encouragement to keep going and get the book finished. Tom and Cora deserve a special thanks for the illustrations of statisticians. The Javamen supplied the coffee. Finally, I would like to thank Sandeep Kumar, Yogalakshmi Mohanakrishnan, Thaatcher Missier Glen, Mary Aswinee Anton, James Schultz, Madeleine Hurd, and Hayley Wood at Wiley’s for bearing with me over the years, and for their support, patience and encouragement.

      About the Companion Website

      This book is accompanied by a companion Website:

      www.wiley.com/go/nelson/statistics

      The Website includes:

       Datasets

       Learning resources

       Teaching notes

PART 1 SETTING THE STATISTICAL SCENE

      Learning Objectives

      You should be reading this textbook because you want to:

       Learn how to design and analyze research projects

       Develop the skills to communicate the results and inferences from research

       Learn to evaluate the scientific literature

      The ideas upon which these skills are founded – an understanding of the scientific method, an introduction to different models of scientific investigation, and the statistical tools to understand the significance of research findings – form the core of this book. Practical, worked examples are used throughout to facilitate an understanding of how research methods and statistics operate at their most fundamental level. Exercises are given at the end of each chapter (with detailed, worked solutions at the end of the book, with more examples and solutions online) to enable you to learn for yourself how to apply and interpret the statistical tools.

      Approaching the Statistician

I have a grown‐up son and a grand‐daughter, age 6 and ¾. They are both very artistic. When I asked them to put their heads together and draw a picture of a statistician by way of illustration for this book, this is what they came up with (Figure 1):

      ‘What’s that!’ I cried. ‘He’s hideous!’

      ‘Well’, they explained, ‘the eyes are for peering into the dark recesses of the student’s incompetence, the teeth for tearing apart their feeble attempts at research design and statistical analysis and reporting, and the tongue for lashing them for being so stupid’.

‘No, no, no’, I said. ‘Statisticians are not like that’. So here was their second attempt (Figure 2):

      ‘That’s better’, I said.

      They interpreted the new drawing. ‘Statisticians may appear a bit monstrous, but really they’re quite cuddly. You just have to become familiar with their language, and then they will be very friendly and helpful. Don’t be put off if some of them look a bit flabby or scaly. This one can also recommend a great dentist and a very creative hair‐stylist’.

FIGURE 1 A SCARY STATISTICIAN.

      Using