Research philosophy refers to the development of knowledge adopted by researchers in their research (Saunders, Lewis, & Thornhill, 2009). In other words, it is the theory that guided the researcher in conducting the procedure of research design, research strategy, questionnaire design and sampling (Malhotra, 2009). It is very important to have a clear understanding of research philosophy so that we can examine the assumptions about how we perceive the world, which are contained in the research philosophy we choose, knowing that they are appropriate or no (Saunders, Lewis, & Thornhill, 2009). According to Saunders, Lewis, and Thornhill (2009), three main ways of thinking about research philosophy are examined: ontology, epistemology, and axiology. Each of these has significant differences that will impact how we think about research procedures. Ontology "is concerned with the nature of reality", while epistemology "is concerned with what constitutes acceptable knowledge in a field of study and axiology "studies judgments about value" ( Saunders, Lewis and Thornhill, 2009, p110, p112, p116). This study aims to create “facts” from objective evaluations made by subjects. Therefore, epistemology will be chosen for this study as a way of thinking about the philosophy of research. Specifically, epistemology also contains three philosophical positions: positivism, realism, and interpretivism (Saunders, Lewis, & Thornhill, 2009). The position of positivism generally supports the investigation or study of an observable social reality and the final output might be "generalizations similar to those produced by physical and natural scientists" (Remenyi et al. cited in Saunders, Lewis and Thornhill, 2009, p113). . It is effective to generate a research strategy to collect credible data from observable reality, thereby contributing to the development of hypotheses (Saunders, Lewis, & Thornhill, 2009). In this study, we aim to explore individuals' credible and measurable outcomes to understand the influence of surprise on viral marketing via social media from the perspective of message characteristics. Thus, the philosophy of positivism will be adopted in this study to collect credible data from the subjects in order to produce “law-like generalizations”. However, it is still difficult to decide whether interpretivism should be applied to conduct a deeper analysis relating to the subjects' attitude for the sake of accuracy. More complicated, such a dilemma would often lead to thinking about realism, which is divided into direct realism and critical realism (Saunders, Lewis and Thornhill)., 2009).