This book is an introduction to quantitative research in the scientific and health disciplines. The whole research process is introduced, from asking a research question to analysis and reporting of the data. The focus, however, is on the analysis of data.
To support this textbook, the following are also available:
- A Tutorial Book; and
- A Software Support Book with brief instruction for using jamovi and SPSS to perform some of the analyses in this book.
These books are both freely available online.
Almost every data set used in this book is a real data set. Many are available electronically so that you can download them and work with them in statistical software. These are listed in Appendix A. Some data sets are taken from Smyth (2010).
Most of this book can be read without relying on any specific statistical software. However, some parts explicitly mention and refer to jamovi (The jamovi Project, n.d.) and/or SPSS (IBM Corp, 2016). jamovi is free and is like (but not exactly the same as) SPSS. From the jamovi homepage (sic):
jamovi is a new '3rd generation' statistical spreadsheet. designed from the ground up to be easy to use, jamovi is a compelling alternative to costly statistical products such as SPSS and SAS.
Navigation: Navigate between pages as follows:
- The left-side menu is for navigating between chapters.
- The right-side menu is for navigating between the sections of the current chapter.
- Words can be searched for using Search button on the menu:
The book is optimised for online viewing, and the book may be updated frequently, so a printed PDF version may not be the most recent version.
In some places, interactive 'quiz' questions are given. In the online version, the background turns from red to green when the answer is correct. Try it now:
- What is \(1+1\)?
- What is \(1+2\)?
- Is \(2 + 2=4\)?
- Which one of these is FALSE?
The icons used in this book have meanings; for example:
These chunks introduce the objectives for the chapters of the book.
These chunks highlight common mistakes or warnings, about a particular concept or about using a formula.
These chunks offer helpful information.
These chunks refer to text that is relevant to using software (jamovi or SPSS) or a calculator.
These chunks indicate how certain symbols and terms are pronounced.
These chunks give you some questions to think about.
This textbook is free for anyone to use: There is no charge for students, instructors or institutions.
Although it is not essential,
an email to the author (explaining how the textbook is being used, who is using the textbook, and your thoughts on the textbook) would be appreciated:
pdunn2 <at> usc.edu.au.
Numerous other R packages were used too:
- The diagrams were made in base R, or using the diagram package (Soetaert, 2017).
- The animations in the html version were made using the animation package (Xie, 2013), and the stills for the PDF version captured by the webshot package (Chang, 2018).
- The gifski package was used to create animations in the online version (Ooms, 2018).
- The kableExtra package was used for nicer tables (Zhu, 2018).
- The maps of Australia were generated using the oz package (Venables & Hornik, 2016) and plotted using the ggplot2 package (Wickham, 2016).
- The display of some data tables in the online version use the DT package (Xie et al., 2018).
- Some plots use the plotrix package (Lemon, 2006).
- The NHANES data is provided by the NHANES package (Pruim, 2015).
- Some data are from the GLMsData package (Dunn & Smyth, 2017).
- The scales package is used to rescale data (Wickham, 2018).
- The carousels in the online version (for example, Sect. 34.3) are made using the slickR package (Sidi, 2018).
- The dygraphs package (Vanderkam et al., 2018) is used to make interactive graphs (for example, Sect. 12.7.4) for the online version.
- The plotly package (Sievert, 2018) is used to make some interactive graphs (for example, in Sect. 12.2.3) for the online version.
- The dplyr package is used in some data manipulations (Wickham et al., 2019).
- The viridis package is used for some colour specifications (Garnier, 2018) to make colours easier for those with colour-blindess to distinguish colours, and for better greyscale printing.
- The webexercises package was used to create the interactive web exercises (D. Barr & DeBruine, 2021).
- The plotfunctions package was used to add images to existing plots (van Rij, 2020)
All of this software is free and open source.
Other resources used include:
- The quizzes are embedded using H5P iframes.
- Icons are from iconmonstr and are freely available.
- The images of the cards used in Sect. 15.2 are from https://code.google.com/archive/p/vector-playing-cards/, and are in the public domain.
- The text folding (in the html version) was implemented by adapting advice from StackOverflow.
- The images of dice used in, for example, Sect. 16.2, are from https://www.clipartkey.com/, and are free.
- The cover for the book was made using a free image using Canva.
- The images used in the online book are free (and used according to their guidelines), as listed in Appendix F.
In this book, you will learn to:
- Develop quantitative research questions and testable hypotheses.
- Design quantitative studies to answer simple quantitative research questions.
- Select and produce appropriate graphical, numerical and statistical analyses.
- Select, apply and interpret the results of the correct statistical technique to analyse data.
- Comprehend, apply and communicate in the language of research and statistics.
- Demonstrate professional integrity in planning, interpreting and reporting the results of quantitative studies.