Meaningful experiments by design

Experimentation is a rather difficult research method to adopt. Even more difficult is studying human participants. Furthermore, only a handful of research programmes can fulfil the criterion of being meaningful. With its focus on “meaningful experiments involving human participants,” this book is a welcome source of knowledge and insight regarding the experimental method. It is useful for beginners as well as experts. Beginners would find the concepts and techniques of experimental design easy to follow without any requirement of extensive knowledge of mathematics or statistics. Experts will be happy to revisit many sections to have a clear grasp of concepts, clarifying doubts, and understanding debates. The author speaks to audiences in a wide variety of scientific disciplines which use the experimental method but are not rigorous enough because they deal with human participants. The book reveals an appreciation of the problems that are concomitant with research on human beings and primarily teaches us techniques to solve these problems through the principles and strategies it enunciates. Part 1 is an introduction to the scientific process of experimentation and focuses on how experiments allow causal inferences. Not only does this section describe why we should choose experimentation rather than any other method of scientific research, it also clearly delineates the limitations of experiments and elucidates important principles of design which lead to correct interpretations as against the common pitfalls which lead to erroneous or incomplete conclusions. Thus, this section gives the reader the rationale for choosing experimentation over other methods and inter alia introduces the basic principles of good experimental design. Part II delineates and describes the various research designs—ranging from those with a single independent variable to complex longitudinal designs. The introductory chapter of this section links to the previous chapter and section as it reiterates the importance of the control group. It further discusses issues in the selection of an adequate and relevant control group, the experimental strategy of random assignment of participants to groups, and problems associated with attrition of participants. Subsequent chapters in this section focus on the between-subjects single-factor design, factorial designs, and repeated measures (within-subjects) designs. The last chapter also introduces the experimental strategies of counterbalancing and blocking. Thus, this section gives the reader all the information needed to select the experimental design and strategies appropriate to his or her purpose. Part III gives the information requisite for “good” experiments. One chapter describes the strategies to be used to maximise the power of experiments. It discusses issues such as sample size, significance levels, and their relation with maximising statistical power. The solutions offered are all considerations important at the design stage of experiments. Thereafter, the second chapter in this section describes issues in the conduct of experiments. It exhorts us to construct a manual of operating procedures so that all concerned people conduct the experiments in a uniform and standard way. The chapter begins with what “not” to share with experimental staff and then describes all aspects which must go into the manual, namely, recruitment, implementation of experimental conditions, data collection, training of research staff, pilot study, and documentation. It gives useful guidelines for the conduct of experiments to mitigate the anticipated problems and ends with a discussion of data handling issues such as data entry, protection, and analysis. Although there is no detailed discussion of analytic procedures, the author does exhort the readers to develop sufficient statistical expertise to analyse data themselves or at least understand and evaluate what has been analysed by others. Part IV is seemingly a motley collection of issues. Nevertheless, this section is crucial because it enables the reader to think beyond the basics and grapple with issues in applied research, which are all the more complex in the context of human research. The section begins with a chapter on external validity (generalisability) of experiments, clarifying the concept of external validity, discussing the questions that must be answered to ensure generalisability (as per Green & Glasgow, 2006). The author further suggests pragmatic trials, meta-analysis, multi-centre experiments, and replication experiments as four strategies to enhance generalizability. The next chapter discusses the use of experimental designs in single-case experiments, Meaningful experiments by design 10. 1177_1747021817743485QJP0010. 1177/1747021817743485The Quarterly Journal of Experimental PsychologyBook review book-review2017