This study employed mixed methods as the research methodology. The term mixed methods as used in this study refers to “an emergent methodology of research that advances the systematic integration, or mixing, of quantitative and qualitative data within a single investigation or sustained program of inquiry” (Wisdom & Creswell, 2013, p. 1). This combines both quantitative and qualitative research methods. Using a quantitative method involves transforming data into a numerical form and analyzing by means of quantitative analysis techniques e.g. statistical methods (Azorin & Cameon, 2010). Meanwhile, qualitative method involves collecting data in textual or narrative form and analyze by employing qualitative data analysis techniques e.g. identifying recurring theme (Creswell, 2013). So, the philosophical assumption connected with the use of mixed methods in this study is situated within pragmatism as it combines detailed descriptions (qualitative) and numerical (quantitative) explanations of collected data in answering the research questions. Pragmatists do connect the choice of research approach directly to the nature of the study, research problems and the kind of research questions guiding the study (Creswell, 2012).
Choosing mixed methods in this study was based on three reasons. The reasons include: an underlying principle investigating an issue requires different research methods; the fact that this study explores a social issue; and the need of mixing both qualitative and quantitative methods in the process of analyzing the same data. First, it was based on the underlying principle that investigating an issue holistically from different perspectives requires different research methods. In support of that, Frels and Onwuegbuzie (2013) argued that the fundamental premise of mixed methods is that integration of the two methods involved may give a better understanding of the research problems and complex phenomena than individual approach does alone. So of all the factors that made a mixed methods approach preferable in this study is the offered opportunities to access multiple perspectives of the development of a complex TSPCK construct (Loughran, et al. 2012), specifically in a population (pre-service teachers) traditionally known to have poor PCK in general (Mavhunga & Rollnick, 2013). Furthermore, its ability to
35
extract aspects of the construct that cannot be reached by quantitative and qualitative means is singly desirable. Varied perspectives were accessible from the two approaches and so the use of the method provided a more complete investigation (McMillian & Schumacher, 2010).
Second, the mixed methods is further recognized to be of active roles in studies that explore social related issues and the significance of intervention programs in addressing such (Luft, Firestone, Wong, Ortega, Adams & Bang, 2011). In this study, the pre-service teachers were involved in the process of learning to teach by developing their PCK within a topic. Maries and Singh (2013) referred to such student teachers’ learning as a social activity. As reviewed in the literature chapter, PCK is a specific knowledge of a teacher that must be learned. Thus, the pre- service teachers learn to develop as they engage in the process of learning to teach. Smith and Banilower (2015) attested to the argument that “PCK is a complex, multidimensional construct specific to a topic/idea” (p. 99) and hence, TSPCK in this study. So, developing pre-service teachers’ TSPCK becomes a social issue as they learn to teach. As a result, the potent of using a mixed methods approach in this study is found in examining the complex nature of the pre- service teachers’ PCK in the two physics topics (kinematics and electricity). Examining this basically encompasses the pre-service teachers’ engagement of cognitive ability while reasoning through the components of TSPCK. This is based on their ability to apply the learnt pedagogical transformation skills in planning kinematics for conceptual understanding. Additional thing to that is the pre-service teachers’ transferability of the learnt pedagogical transformation competence in planning and teaching a new physics topic (electricity) not discussed in the intervention. Such an examination requires a research design that gives an in-depth understanding with valid reasons and evidence. This makes a mixed methods design most appropriate in this study.
Third, in this study the qualitative method was more suitable to gather evidence of developing TSPCK as the pre-service teachers engage in the process of planning for teaching a physics topic in both the topic of learning and that of transfer. Moreover, the quantitative method which involves statistical analysis was found useful in determining the extent to which improvement in the quality of TSPCK in the topic of intervention has occurred. Also, the method was found useful in determining the extent at which transfer of the learnt pedagogical transformation competence has occurred. However, of interest is the mixing of the methods where: the TSPCK
36
tools used were of qualitative information analyzed quantitatively by scoring in reliable way, converted to measures placed on a scale with equal intervals from which reliability and validity are calculated; findings from each methods were used for triangulation or confirmation, with respect to that, scoring responses were compared among two raters and agreement reached for reliability. The two methods would be establishing the validity and trustworthiness of the data and research findings. In this way, the argument by Ocathain, Murphy and Nicholl (2008) is justified that it is required of a research to illustrate in what way the mixing happens, where it happens and those who are affected by the mixing, whenever a mixed methods approach is applied in research studies. A mixed methods design can also generate a truthful and enlarged level of confidence in the results obtained from the research (Schram, 2014); give clarification of the individual opinion of those who participated in the mixing (mixed methods study) (Schram, 2014). Thus, the use of mixed methods for this study gave the enabling benefits of studying pre- service teachers’ development of TSPCK in kinematics and transferability of the learnt pedagogical transformation competence to a new physics topic.