The discourse of causal explanations in school science
Creators: name: Slater, Tammy Jayne Anne
Publisher: name: University of British Columbia
Year: 2009

description: Researchers and educators working from a systemic functional linguistic perspective have provided a body of work on science discourse which offers an excellent starting point for examining the linguistic aspects of the development of causal discourse in school science, discourse which Derewianka (1995) claimed is critical to success in secondary school. Yet the work that has been done from this perspective has generally focused on texts in science books and encyclopedias, or in other words, texts written by expert writers (e.g., Mohan et al., 2002; Veel, 1997). A notable exception is Gibbons (1998, 2003), who used data from an elementary ESL science class to illustrate the move from hands-on, context-dependent discourse to the decontextualized forms characteristic of science writing, and the role of the teacher in providing the necessary scaffolding to make this move successfully. No work has yet described the development of causal language by identifying the linguistic features present in oral discourse or by comparing the causal discourse of native and non-native (ESL) speakers of English. The current research responds to this gap by examining the oral discourse collected from ESL and non-ESL students at the primary and high school grades. Specifically, it asks the following questions: 1. How do the teachers and students in these four contexts develop causal explanations and their relevant taxonomies through classroom interactions? 2. What are the causal discourse features being used by the students in these four contexts to construct oral causal explanations? Ethnographic data collection involved recording observations of classroom interactions (244 recorded hours) as well as formal and informal interviews (9+ hours), which were transcribed and coded to reveal (1) how the teachers built up key concepts through their implementation of the two types of linguistic patterning which Halliday (1998) claimed is involved in constructing science knowledge—the creation of technical terms and chains of logical reasoning—and (2) the causal discourse features which were used by the students to construct their explanations. A social practice analysis revealed the similarities and differences which existed among the four contexts studied with regard to the teachers' ways of developing the ability to explain and construct science knowledge, and a small corpus study helped to show the patterns of development across the same four contexts. Concept maps (Novak, 1998), built from the discourse of the classroom interactions, offered graphics to illustrate the knowledge which was constructed through the classroom discourse. The findings of the social practice analysis showed that the teachers in the four contexts differed in their approaches to teaching, with the primary school mainstream teacher focusing largely on the hands-on practice, the primary school ESL teacher moving from practice to theory, the high school mainstream teacher moving from theory to practice, and the high school ESL teacher relying primarily on theory. Although no causal connections can be made from this study regarding the effectiveness of one approach over another, the findings appear to reflect the popular practice of using hands-on, minds-on approaches to teaching and learning science. The study therefore contributes a new, linguistic perspective to work which has been and continues to be carried out in science education. The findings from the quantitative, small corpus approach suggest that the developmental path of cause which has been identified in the writing of experts shows up not only in written texts but also in the oral texts which learners construct. Moreover, this move appears when the discourse of high school ESL and non-ESL students is compared, suggesting a developmental progression in the acquisition of these features by these students. The findings also reveal that the knowledge constructed, as shown by the concept maps created from the discourse, follows a developmental path similar to the linguistic causal path, from the concrete, hands-on, observable items to more abstract, theoretical concepts. This study is the first systemic functional comparison of the oral discourse of primary and secondary learners as well as the first to compare ESL and non-ESL speakers in this way, and as such it helps map general trends in causal discourse development.