It is hard to study statistics unless you have some understanding of the research methodology that generates the data produced for statistical analysis. It is also hard to study research methods without understanding the basics of statistical procedures. Psychology departments often struggle with which course students should take first. Some departments have even tried to teach the courses together.
The approach that we have taken with our research methods text is that it is impossible to understand research methods without some appreciation for statistical procedures, because selecting the appropriate statistical procedure is a critical part of designing research studies. Therefore, we provided the very basics of statistical methods in the text and included a section in Appendix D designed to help students select the appropriate statistical procedures from the vast array of procedures available. We have also included on the Student Resource Website instructions on how to perform basic analysis (either manually or using SPSS for Windows), as well as conceptual explanations of statistical procedures and the principles behind them. We leave it up to the instructor and student to decide how much detail they want to include. A student who carefully studies all of the statistical material in the textbook and on this website will have completed the equivalent of an undergraduate course in psychological statistics.
Statistics are a tool, and the better you understand statistics, the better use you can make of this tool in your own research. It is no accident that graduate training in psychology includes extensive statistical training.
Advances in statistics and research methodology has helped to fuel many of the advances in understanding psychological functioning. But our point throughout this research methods textbook is that it is not the technology nor the tools that make a scientist. It is the ability of the scientist to think through a problem and apply those tools and technologies to solving that problem.