1.1 History

In the eighteenth century, French sociologist Pierre Guillaume Frederic Le Play conducted what later came to be known as the case study method. Le Play’s Les Ouvriers européens took 25 years of exploration of the European working men (Mogey, Reference Mogey1955). His book was published in 1855 and included case studies of 57 families, each one of them representative of a specific working class. Le Play’s approach, which might seem obvious today to anyone with a little knowledge of case study methods, was a breakthrough at that time. It is notable that any strides which case study research has made in the past two centuries is built upon Le Play’s labor and methodological invention. Today, even 167 years later, we cannot but marvel at the ingenuity, time, and effort that Le Play put into exploring the lives of the working class firsthand. Since Le Play’s days, social sciences have seen a multitude of case studies. From unique cases which opened the doors for investigating some previously unexplored phenomenon to typical cases which helped in reaching generalizable solutions to problems, the nature and scope of case study research nowadays is manifold.

Some remarkable examples of case studies could be found in social sciences. For instance, the (now) popular Phineas Gage is one of the earliest case studies in psychology and neuroscience. In 1848, Phineas Gage, a construction supervisor in Vermont, succumbed to an accident. Gage was preparing the powder charge for blasting a rock and accidentally forced a steel rod into the hole. The resultant explosion pierced his skull and damaged his frontal lobe. Surprisingly, Gage recovered from this injury. However, as his friends opined, “Gage was no longer Gage.” His behavior changed completely. From being an even-tempered man, Gage became an antisocial person who would shout expletives and indulge in bad manners and dishonest behavior (Sabbatini, Reference Sabbatini1997). By observing Gage’s behavior and interviewing his acquaintances, Gage’s doctor John Harlow wrote two books on how the frontal lobe plays a role in the decision-making and social cognition of human beings. Contrary to what most sources say on the topic, there has also been some evidence to the fact that Gage eventually recovered from his wayward behavior and was leading a peaceful life (Costandi, Reference Costandi2018). It is difficult to know whether stories about his subsequent life are fact or fiction. Regardless, Phineas Gage’s case is the first to point to the role of the brain in human behavior. Gage’s case is explored even today by scientists (Why Brain Scientists are Still Obsessed with the Curious Case of Phineas Gage, 2017). For instance, in 2012, Van Horn and colleagues compared the CT scans of Gage’s skull with the MRI scans of typical brains to further explore the effect of frontal cortex damage on behavioral changes (see Van Horn et al., Reference Van Horn, Irimia, Torgerson, Chambers, Kikinis and Toga2012).

Another example of a popular case study in psychology is that of Genie,Footnote ¹ a pubescent girl who lived most of her life in social isolation, deprivation, and abuse. She was discovered when she was 13 years old. Genie was emotionally disturbed, uncoordinated, underweight, and could not speak any language. Further investigation revealed that Genie was raised in complete isolation, in a small, closed room where she was often tied to a potty chair. She only wore a cloth harness, which prevented her from handling her feces. She was fed very little food, often in the form of baby food, and was minimally cared for by her mother. Genie never had an opportunity even to watch television, listen to radio, or hear other people talking, since her father was intolerant to any noises. She was punished if she ever made any sounds (Fromkin et al., Reference Fromkin, Krashen, Curtiss, Rigler and Rigler1974). The pathological behavior of the family members and the impoverished environment she grew up in led to Genie being alarmingly slow in her development. Genie’s case was investigated by researchers in psychology and linguistics to understand the relationship between language and cognition as well as the mental abilities, the stages, and the biological foundations underlying language acquisition and competence (Curtiss et al., Reference Curtiss, Fromkin, Krashen, Rigler and Rigler1974). From the neuroscience study of Phineas Gage in the eighteenth century to the more recent linguistic study of Genie, case studies have evidently facilitated understanding regarding different aspects of individual and social behaviors.

Similarly, in the field of political science, Theda Skocpol’s (Reference Skocpol1979) book was highly influential. In the book, she explored the reasons that lead to social revolutions. For this purpose, she conducted a comparative case study. She compared the countries in which a social revolution had happened (France, Russia, and China) with countries in which a social revolution had not happened (England, Prussia/Germany, and Japan). To undertake these cross-case comparisons, she applied the classical Mill’s methods of difference and agreement which aimed at identifying causal relationships between the variables of interest. This allowed her to identify “causes” that can lead to “social revolution.”

Similarly, in the field of sociology, a classical case study is that of Middletown (Lynd & Lynd, Reference Lynd and Lynd1929, Reference Lynd and Lynd1937). In their seminal work, the Lynds studied a typical small American city. The Lynds had cleverly anonymized the city that they studied by calling it Middletown, since many places in the United States are called Middletown. Nonetheless, it was eventually found out that the city subject to their analysis was Muncie, a city in Indiana. Regarding the Lynds’s seminal work, Sarah Igo’s (Reference Igo2007) following book passage captures how deeply the Lynds had immersed themselves into the field, with the goal to understand the city and its residents better:

You could ask why the Lynds wanted to study this particular city. Well, by selecting Muncie, a city that represented the average typical cities in the United States, the Lynds could easily “transfer” insights derived from it to other cities that shared a similar context. Moreover, the Lynds also went on to compare Muncie as it existed during two time periods – before the Great depression (Lynd & Lynd, Reference Lynd and Lynd1929) and during the Great depression (Lynd & Lynd, Reference Lynd and Lynd1937). Looking at the same city allowed them to control (i.e. keep constant) contextual factors that were of no theoretical interest to the study in hand. At the same time, it allowed them to identify causal factors that were affecting activities since the commencement of the Great depression.

Last but not least, in the field of management, case study research has been instrumental in providing important groundbreaking insights. For example, Vaccaro and Palazzo (Reference Vaccaro and Palazzo2015) use a case study to understand how institutional changes could happen in a context that is fraught by organized crime. To understand this, they looked at a movement called Addiopizzo that originated in 2004 in Palermo, Sicily. The movement was started by a young activist who wanted to stand up against extortion money (also known as pizzo) that was being demanded from Sicilian businesses by the Mafia. Paying the pizzo was seen as paying protection money. Similarly, anyone challenging the pizzo was considered as challenging the Mafia’s sovereignty and often met with three risks – encountering violence (e.g. death), economic losses (e.g. a business being burnt down), and social isolation. It is surprising to see, therefore, that in such a context Addiopizzo went on to become one of the most successful anti-Mafia movements. In fact, Vaccaro and Palazzo (Reference Vaccaro and Palazzo2015) indicated that, by 2011, reports on extortion saw an increase, which was unprecedented since in the past people did not report Mafia atrocities out of fear. Moreover, the movement was able to garner significant support by “56 activists, 10,143 consumers, 154 schools, 29 local associations (e.g., the Sicilian branch of Confindustria, the highly influential Confederation of Italian Industry), and more than 700 affiliated firms (over 10% of the entrepreneurs in the Province of Palermo)” (Vaccaro & Palazzo, Reference Vaccaro and Palazzo2015, p. 1080).

The success of the movement challenged the entrenched belief that nothing can be done about the pizzo. Furthermore, this also made for an interesting case to study and understand. Given this pivotal role case studies have been playing in the social sciences, it is important to answer the question – What exactly is a case study?

1.2 Case Study: What Is It?

Robert Yin, the American social scientist known for his extensive work on case study research, defines the case study as an empirical inquiry investigating a contemporary phenomenon in its real-life context (Yin, Reference Yin2009). In Yin’s definition, the case studies investigate phenomena of interest which do not have clear boundaries separating them from the context. Usually, these phenomena involve multiple causal conditions and a relatively lower number of data points. In case study research, phenomena are explored using multiple sources of evidence, with the help of pre-developed theoretical propositions. Since case studies by definition involve small sample sizes, the appropriate selection technique is purposive rather than random. The cases, as well as the participants and data sources, are selected in such a way that they are representative and provide variation along the causal conditions and outcomes which are of interest to the researcher (Gerring, Reference Gerring2007). In general, a case study is the focused study of a bounded phenomenon through intensive exploration (Gerring, Reference Gerring2004). For instance, if the focus of a particular case study is understanding the eLearning experiences of Master students in a business school, the researcher can select a specific business school providing eLearning facilities for its students as the case. This case could be typical (as was in the Middletown example), as in, similar to other business schools with eLearning facilities. It could also be chosen because of its atypical nature, that is, due to it being an exemplar in providing eLearning facilities (as was in the Addiopizzo example). Regardless of the specific reason behind the choice, case selection in case study research always involves careful contemplation of the suitability of a particular case for the study. The reasons behind the choices are often determined by the specific study’s research questions and, subsequently, by its designs.

1.3 (Sequencing) Case Study Designs

Yin (Reference Yin2009) suggested four types of case study designs based on the number of cases and sub-cases being investigated. Based on whether a case is single or multiple and embedded or holistic, he proposed the single holistic, multiple holistic, single embedded, and multiple embedded designs. Gerring (Reference Gerring2004), on the other hand, provided a covariational typology of case study designs based on the spatial and temporal variations that underlie them. Subsequently, the within-unit (with and without temporal/spatial variation), cross-sectional, time-series cross-sectional, hierarchical, comparative–historical, and hierarchical time-series designs became a part of the case study vocabulary. Blatter and Haverland (Reference Blatter and Haverland2012) added to the conversation on case study designs by suggesting three ways of conducting causal case study research – co-variational analysis, causal–process tracing, and congruence analysis. In this book, we add to the discussions on case study designs by proposing a technique that we call “sequencing case study designs.” Traditionally, sequential research designs were introduced to reconcile the use of qualitative and quantitative research methods in the same study (Cameron, Reference Cameron2009). Different authors have discussed sequential designs based on the timing, weighting, and ordering of methodological choices (Cresswell et al., Reference Creswell, Plano Clark, Gutmann, Hanson, Tashakkori and Teddlie2003). However, our new proposed design technique (i.e. sequencing case study designs) is novel on two aspects. First, it squarely focuses on qualitative case study designs. Second, this technique incorporates the malleable nature of case study designs by (re)combining the strengths of individual case study designs to suit the unique needs of a research study in hand.

1.4 Purpose of This Book: From Sequencing Case Study Designs to Undertaking a Methodological Tango!

The discussion on case studies and designs brings us to the core purpose of the book. Case study research is a versatile method in that it allows for different data sources (be they qualitative or quantitative) to be combined in the same study. Its main purpose is theory enhancement (theory building and rarely also theory testing). The method has become a mainstay in the social sciences, resulting in a myriad of methodological textbooks and articles, some of which date back to the 1970s (e.g. Campbell, Reference Campbell1975). Despite its popularity, the case study research has been prone to criticism regarding academic rigor and ambiguity (Dubé & Paré, Reference Dubé and Paré2003; Gibbert et al., Reference Gibbert, Ruigrok and Wicki2008). This book makes four important departures from apparently competing works currently on the market: First, whereas previous case study method books focused on combining data sources within one design, we combine designs and streamline our discussion specifically on designing as opposed to data collection and data analysis. In doing so, we take case study research to the next level by discussing the combinations of different case study designs in the same research study, which we describe as “sequencing case study designs.” Our approach is similar to experimental methods in which we find several (typically four-to-six) individual experiments in the same paper, with increasing sophistication and rigor.

In this book, we first provide the essential building blocks of case study research designs. We subsequently discuss archetypical research designs in terms of their strengths and weaknesses, and ultimately proceed to illustrate how these can be fruitfully combined depending on the research question. We discuss the relevant methodological choices on each level, with an eye on maximizing the contribution of the case study for theorizing. We submit that the rigor of the overall series of case studies is greater than the sum of its parts, since combinations of different case study designs embrace different epistemological traditions and cut across rigor criteria. This discussion on case study designs is, hence, the first focal point of this book.

Second, there is a conundrum: case studies are most appropriate in the early stages of theory development, yet often get rejected for the lack of theory in the front end of the paper (despite otherwise rigorous methods). Thus, while its prowess for theory development is unquestioned and in fact touted as the main rationale for case study research, the currently-available books have so far not effectively engaged in the mechanics of crafting and relaying the theoretical contribution cogently to different reviewer camps. We address this conundrum in this book. Third, rather than providing normative prescriptions of what authors should do based on reviews of the methodology literature (as is common in extant methodological books), we provide concrete examples to illustrate both individual case study designs, as well as their combinations. These examples stem from over 30 years of research into case study rigor by the authors, and 15 years of teaching the case study method to students at all levels.

Fourth, given the lack of cohesion in the conventions surrounding case study research (interpretivists describe their research design in totally different ways than, say, those in more positivist traditions), we undertake a methodological tango! That is, we move back and forth between the intricacies of interpretivist and positivist traditions, by highlighting their differences but also similarities. Through this methodological tango, we acknowledge the different traditions but also discuss how dismissing one tradition or the other stating dogmatic reasons might defeat the purpose of case study research (which is developing a better understanding of the phenomenon of interest). We, therefore, choreograph this methodological tango by providing “box inserts” under the heading “But someone told/asked me” throughout the book. In these box inserts, we tease out the intricacies of case studies and their designs. These boxes are designed to make the book more helpful for different audiences – the instructors of case study courses and the researchers interested in conducting case study research. Additionally, we also include box inserts that act as thinking exercises under the name “But before we move on let’s think/read/watch.” The instructors of case study courses will find these box inserts useful for designing their courses; while practicing researchers will appreciate the box inserts for the concrete guidance on improving their own case study designs.

1.5 Summary of the Chapters

In Chapter 2, we discuss the building blocks of case study research. We discuss the various functions that case study research can play and the resultant types of research questions. The importance of context in case study research is examined afterwards. Furthermore, we introduce the logical reasoning concepts of induction, deduction, and abduction to the readers. In the subsequent chapters, we discuss different case study designs. We begin to do so in Chapter 3, which focuses on the single case study design. The strengths and weaknesses of a single case study design are elaborated upon. In Chapter 4, we discuss the multiple case study designs, with a focus on replication logic. Both literal and theoretical replication are introduced, along with their strengths and weaknesses. The rigor parameters of reliability, internal validity, and external validity are also discussed in this chapter. At the end of the chapter, we also discuss the strengths and limitations of the multiple case study design. In Chapter 5, we discuss single embedded case studies. The levels of analysis and selection rationales underlying single embedded designs are deliberated upon. Longitudinal and cross-sectional single embedded designs are discussed afterwards. The strengths and weaknesses of single embedded designs are discussed at the end of the chapter.

Chapter 6 deals with multiple embedded case study designs. The different levels of analysis and units of analysis as well as within- and between-case replications are discussed in this chapter. We end the chapter with a discussion of the strengths and weaknesses of the designs. In Chapter 7, we discuss the sequencing of inductive–deductive case study research designs. We revisit the topics of research questions, theoretical sampling, controls, and units/levels of analysis in the context of the sequenced designs. The importance of chronology in sequencing designs is discussed last. Chapter 8 deliberates on the deductive–inductive sequencing of research designs. Like in the preceding chapter, we discuss research questions, theoretical sampling, controls, and units/levels of analysis in the context of this type of sequenced research designs next. The importance of additional data collection and transparent reporting is then elaborated upon. We end the chapter with a discussion of deviant cases and the omitted variable bias. Finally, in Chapter 9, we revisit the research paradigms of positivism and interpretivism and subsequently discuss different quality criteria proposed by prior researchers from both paradigmatic camps. We also briefly discuss the iterative cycles of data collection and analysis one would encounter during a qualitative case study research process. We end the chapter and the book by offering a guiding framework for researchers interested in sequencing case study designs.