International Journal of Recent Innovations in Medicine and Clinical Research Open Access, Peer Reviewed, Abstracted and Indexed Journal ISSN: 2582-1075 https://ijrimcr.com/ Volume-3, Issue-4, 2021: 35-40 35 Research Article An Overview: Epistemological Foundations of the Qualitative and Quantitative Research Approaches Shar Abdullah Alamri, B.Sc., M.Sc., CDNP Physiotherapy Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia. Email: salamri@psmmc.med.sa Received: November 8, 2021 Accepted: December 5, 2021 Published: December 18, 2021 Abstract: The philosophical underpinning of pragmatism allows and guides qualitative/quantitative researchers to use a variety of approaches to answer research questions. Pragmatism's philosophical underpinning permits and directs researchers to use a range of methodologies to address research questions. However, this article provides the philosophical and conceptual framework that informed the two research methodologies and discusses how ontological and epistemological issues were translated in to specific methodological strategies and influence researchers methodological decision. The purpose in writing this article is to describe and reflect on the differences between the two research methodologies from ontological, epistemological and methodological perspectives and how they will be selected for research. Keywords: Epistemology, Ontology, Methodology, Positivism, Interpretivism. Introduction A researcher's beliefs and assumptions about the essential, fundamental characteristics of their research projects influence the philosophical foundations of the research process. Furthermore, one's research approach influences the data collection, analysis, and interpretation processes, all with the goal of reaching a reasonable conclusion. The studies can be influenced by a researcher's beliefs and assumptions, particularly how to apply the positivist and interpretivist paradigms. However, the basic assumptions that serve as a framework for the research are ontology, epistemology, and methodology, which are fundamental principles of philosophy of social science. The purpose of this paper is to identify the key epistemological assumptions that underpin the research by providing basic definitions of the primary principles in social science philosophy, namely ontology, epistemology, and methodology. It also compares the epistemological assumptions of the positivist and interpretivist paradigms. Content analysis and discourse analysis concerns arise from conflicting research approaches based on two major research paradigms, positivism and constructivism, respectively. Philosophical Knowledge Used in Research Philosophical assumptions are defined as a specific set of beliefs and/or assumptions that are used to develop a set of research questions. Guba (1994, p.17) defined "worldview" as "a fundamental set of beliefs that guide action" (1) . However, in order to establish fundamental beliefs that underpin a research paradigm, fundamental questions concerning the nature of reality and humanity (ontology), the theory of knowledge that inform the research (epistemology), and how that knowledge may be achieved, influence the choice of research approach (methodology) (2,3) . Ontology is a technical term in philosophy that refers to the nature of reality. In other words, it is the answer to the question of what kinds of things exist in the world (4) . Blaikie's (1993, cited in Grix, 2004, p.59) definition of ontology apprehension is "claims and assumptions made about the nature of social reality, claims