For the researcher new to using case study, such variety can create a confusing platform for its application. Introduction Case study research has grown in reputation as an effective methodology to investigate and understand complex issues in real world settings.
In this article, we explore the evolution of case study research, discuss methodological variations, and summarize key elements with the aim of providing guidance on the available options for researchers wanting to use case study in their work. Foundational Concepts 3.1 Definitions and descriptions 3.2 Methodology or method 3.3 Philosophical orientation 3.4 Philosophical variation 3.4.1 YIN: Realist—postpositivist 3.4.2 MERRIAM: Pragmatic constructivist 3.4.3 STAKE: Relativist—constructivist/interpretivist 4. Case study designs have been used across a number of disciplines, particularly the social sciences, education, business, law, and health, to address a wide range of research questions.
 In this article, we examine each of these issues in turn, with the aim of improving our understanding of case study research and clarifying the requisite tenets to consider when designing a case study.
We begin with an overview of the history and evolution of case study research, followed by a discussion of the methodological and philosophical variations found within case study designs.
: Over the last forty years, case study research has undergone substantial methodological development.
This evolution has resulted in a pragmatic, flexible research approach, capable of providing comprehensive in-depth understanding of a diverse range of issues across a number of disciplines.Sociologists and anthropologists investigated people's lives, experiences, and how they understood the social and cultural context of their world, with the aim of gaining insight into how individuals interpreted and attributed meaning to their experiences and constructed their worlds (JOHANSSON, 2003; SIMONS, 2009).Such investigations were conducted in the natural setting of those experiences with results presented descriptively or as a narrative (MERRIAM, 2009).This renewed interest in qualitative methodology led to a revival in the use of case study in a number of disciplines (ANTHONY & JACK, 2009; GEORGE & BENNETT, 2005; JOHANSSON, 2003; MERRIAM, 2009; STAKE, 1995).According to JOHANSSON (2003), Robert YIN followed this progress, and drawing on scientific approaches to research gained from his background in the social sciences, applied experimental logic to naturalistic inquiry, and blended this with qualitative methods, further bridging the methodological gap and strengthening the methodological quality of case study research.Change and progress have stemmed from parallel influences of historical transformations in approaches to research and individual researcher's preferences, perspectives, and interpretations of this design.Researchers who have contributed to the development of case study research come from diverse disciplines with different philosophical perspectives, resulting in a variety of definitions and approaches.Central to these variations is the underpinning ontological and epistemological orientations of those involved in the evolution of case study research.Researchers who have contributed to the development of case study research come from diverse disciplines and their philosophical underpinnings have created variety and diversity in approaches used.We end with a summary of the common characteristics of case study research and a table that brings together the fundamental elements that we found common in all case study approaches to research. History and Evolution Case study research as a strategy for methodological exploration, according to FLYVBJERG (2011) "has been around as long as recorded history" (p.302).Contemporary case study research is said to have its origins in qualitative approaches to research in the disciplines of anthropology, history, psychology, and sociology (MERRIAM, 1998; SIMONS, 2009; STEWART, 2014).