The objectives of this research, including the need to investigate school culture within a real- life context, suggested a case study approach as the most appropriate way forward. Gillham (2000) defines a case study as:
A unit of human activity embedded in the real world which can only be studied or understood in context which exists in the here and now that merges in with its context so that precise boundaries are difficult to draw (Gillham, 2000, p. 1).
In short, it is “one which investigates the above to answer specific research question and which seeks a range of different kinds of evidence” (Gillham, 2000, p. 1). Stake (2005) provides an understanding of the uniqueness of a case and how it provides an opportunity to discover something new and innovative. In describing case study research in such personal and specific detail, Stake suggests that a selection of cases and how they are chosen remains central to the validity of a research study. His division of case study into intrinsic,
instrumental and collective provides a useful framework whilst at the same time challenges us to consider the dilemma of knowledge gained from in-depth study of an individual case, versus the generalisations that may emerge from multi case analysis. In his analysis of single and multi-case study research, Stake (2005, p. 6) went on to argue that at the heart of any case is a ‘Quintain’ or phenomenon or condition to be studied. The Quintain can be present in a single case or the ‘holding company’ or ‘umbrella’ for multiple case analysis.
For my purposes, “since the first criterion should be to maximize what we can learn” (Stake, 1995, p. 4) I decided to undertake a multi-case study of amalgamated schools and multi- academy trusts where each school is a case and where the Quintain is ‘school culture’. The objective was to “study what is similar and different about the cases to understand the Quintain better” and consequently develop an understanding of school culture in these different but at the same time similar settings (Stake, 2006, p. 6).
The use of a multi-case study model allowed in-depth analysis of school culture within several settings as well as providing a comparative and longitudinal approach designed to create a greater understanding of how cultures develop, and how it contributes to school
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improvement. With this in mind, it was also important to consider the theoretical basis upon which the approach was chosen and how case study literature helped place the research into context.
In considering the choice between single and multiple case studies, Yin is unequivocal. “When you have the choice” he argues, “multiple case designs may be preferred over single case designs…since your chances of doing a good case study will be better than using single case design” (Yin, 2003, p. 53). Yin also provides useful advice in relation to the selection of cases and whether the design should use replication or sampling logic. Sampling logic, he points out would require an impossibly large number of cases to study whereas replication allows for the comparison of outcomes in the development of a rich theoretical framework (Yin, 2003). The replication logic allowed me to me to duplicate the conditions in each of the cases selected, thus making the findings “robust and worthy of continued investigation or interpretation” (Yin, 2003, p. 47). Yin’s analysis meant I needed to distinguish between multiple case studies which are either holistic or embedded. I used an embedded approach where data was pooled across cases and collected and analysed for each individual case.
Yin offers further advantages where more than one case is used: “multiple case studies can be used to either augur contrasting results for expected reasons or either augur similar results in the studies” (Yin, 2003). In this way the author can clarify whether the findings are valuable or not (Eisenhardt, 1991). When the case studies are compared, the researcher can also provide the literature with an important influence from the contrasts and similarities (Vannoni, 2015). An all-embracing fact is that the evidence created from a multiple case study is measured, strong and reliable (Baxter & Jack, 2008). Other advantages of multiple case studies is to create a more convincing theory when the suggestions are more intensely grounded in several empirical evidence. Thus, multiple cases allow wider exploration of research questions and theoretical evolution (Eisenhardt & Graebner, 2007).
In the multiple case studies design, there are no explicit conditions about the number of cases needed to legitimise outcomes, Yin says that “the typical criteria regarding sample size are irrelevant” (Yin, 1994, p. 50). Instead, he suggests selecting cases “until no significant new findings are revealed” (Yin, 1994, p. 50) and advises participants be selected where the phenomena under study is likely to be found. In assigning my research as ‘comparative’ and ‘multiple’ in design, therefore, I would argue that it has been possible to make some
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legitimate generalisations about school culture as a ‘Quintain’ despite the breadth versus depth trade-off common in case study research (Johnson and Christensen, 2012).
A key aspect of case study and multiple case study research is the process of selecting the cases and the extent to which they will help develop knowledge of the Quintain. Therefore, I decided to apply Stake’s three criteria for selecting the cases:
is the case relevant to the Quintain?
does the case provide diversity across contexts?
do the cases provide good opportunities to learn about complexity and contexts? (Stake, 2006, p. 23).
A further consideration underlined by Stake in adopting multi-case studies is to examine how the Quintain operates in different environments. Therefore, he recommends that typical and atypical settings should be chosen (Stake, 2006). Finally, since case activity is influenced by setting, Stake recommends that the context of each case needs to be studied and described to assess its influence on the case and the Quintain (Stake, 2006). Critics of the case study approach point to the limitations in validity that single sources of primary information generate, and to the relative inability to generalise from a single environment. However, by examining school culture in similar but different environments in three secondary schools, the limitations of the case study model have been further mitigated in this study.