MODELLING-BASED TEACHING IN CHEMISTRY IN A MULTILINGUAL CONTEXT : A tool to explore and visualise the non-spontaneous and abstract?

Sammanfattning: The thesis aims to investigate modelling-based teaching in the multilingual context. Modelling-based teaching concerns when students create, discuss, and evaluate representations to visualise concepts and processes. In this thesis, modelling-based teaching has been used in polymer chemistry at a Swedish secondary school. Data has been collected from eight multilingual groups from three different classes. A total of 30 students participated in the study, 16 students with Swedish as a second language and 14 students with Swedish as a first language. The modelling-based teaching activity has been investigated from several aspects. The first paper focused on if and how second language learners’ conceptual descriptions were affected by modelling-based teaching. The second paper focused on how students’ meaning-making during modelling-based teaching could be detected and analysed from a social semiotic perspective.  The thesis has been conducted from a sociocultural (Vygotsky, 1978; Vygotsky, 1986), a phenomenographic (Marton & Booth, 1997), and a social semiotic perspective (Kress & Bezemer, 2015; Kress, 2001). Empirical data consists of audio and video recordings and photographs taken during the modelling activity, where students in multilingual groups created representations and discussed concepts and processes concerning polymer chemistry. Empirical material, relevant to the intention of what the students should learn from the modelling activity and critical aspects, were transcribed and analysed to answer the following questions: (1) How are descriptions of nonspontaneous concepts in polymer chemistry of second language learners affected by modelling? (2) What social semiotic practices are observed during a modelling activity in a chemistry unit of polymers? (3) How do these practices influence students’ meaning-making of created representations crucial for the understanding of polymeric concepts?    The result for the first research question indicates that the modelling activity contributed to that 101 concept descriptions (65%) showed an increased clarity, and 70 concept descriptions (45%) showed an increased use of chemical concepts, for second language learners. The result highlights how second language learners in a multilingual context develop their language of chemistry by discussing chemistry in a context where they are stimulated to create and modify representations. The results also indicate that the created representations scaffolded students’ chemistry discussions by using the created representations as mediating artefacts when discussing chemistry.  The results for the second and third research questions indicate that translative processes between and within created representations indicate meaning-making for students’ learning of polymeric concepts. As such, the thesis highlights the importance of identifying translative processes during students’ modelling. Furthermore, it is discussed that teachers can use the social semiotic lens as a tool to identify and evaluate students’ meaning-making during modelling-based teaching. The results indicate that created representations were important bridging resources between the submicro and macro levels. This means that the students, with the help of created representations, linked the structure and chemical properties of macromolecules to the properties of different materials. The results also show that the modelling activities practised by all groups were multimodal.   Overall, this thesis highlights the importance of student-active approaches in the chemistry classroom, where students can visualise and discuss the invisible and abstract to develop their language of chemistry. The thesis also contributes to highlighting social semiotics as a tool for teachers to pay attention to students’ meaning-making during modelling-based teaching.