Using semantic profiling to characterize pedagogical practices and student learning : a case study in two introductory physics courses
Framed by the South African imperative of widening epistemological access to undergraduate science studies, this research takes the form of a case study to investigate the educational affordances of an extended introductory physics course. Using theoretical tools from Legitimation Code Theory (LCT) (Maton, 2014a) – in particular, semantic gravity and semantic density – the study characterizes the pedagogical practices and student learning in this Extended course, in relation to a Mainstream course in the same Physics Department. Data was collected through classroom observations, observations of student groups working on Mechanics physics tasks, and interviews with students. Two external languages of description were developed in order to translate between the LCT concepts of semantic gravity and semantic density and the empirical data from the physics context. The first language of description was used to characterize the semantic shifts in pedagogical practices, using a Concrete-Linking-Abstract continuum. The second language of description drew on physics education research on representations (Knight, 2007; Van Heuvelen, 1991a) tasks. Semantic profiles (Maton, 2013) were then constructed to show the semantic shifts in the pedagogical practices and in lecturers’ and students’ approaches to physics tasks. The study has shown that the extra curriculum time enabled different pedagogical practices. The Extended course showed a steady progression in pacing, initially with a less compressed semantic profile, while the Mainstream course showed a consistent compression. The Extended course showed a greater prevalence of the Linking level, with more time spent at the Concrete level and greater semantic flow. The courses also exhibited different communicative approaches, with students in the Extended course more engaged in making the semantic shifts together with the lecturer. The Extended course used more real-life illustrations as a starting point, whereas the Mainstream course tended to use verbal problem statements. Looking particularly at how problem tasks were dealt with, the study suggested that the lecturers’ pedagogical practices in dealing with physics tasks influenced the way in which the students tackled these tasks. The semantic profiles showed a more rapid shift up the semantic continuum in the Mainstream pedagogy and student work, while in the Extended pedagogy and student work, the semantic profiles indicated that more time was spent initially unpacking the concrete problem situation and explicitly shifting up and down the semantic continuum. In terms of methodological contribution, this study has demonstrated the usefulness of LCT tools for characterizing pedagogical practices and student learning in a physics context. Furthermore, the study has linked LCT to physics education literature and to research on epistemological access and academic literacies in a novel way. It has modified Maton’s form of semantic profiling, through introducing the following: a more detailed time scale, gradations of semantic strength on the semantic continuum, and coding for interactive engagement in pedagogical practices. The study thus has important implications for how curriculum and pedagogical practices might better support epistemological access to disciplinary knowledge in the field of physics, not only at the Extended course level but for introductory physics courses more generally.