While appreciating ongoing debates around the nature and role of literacy in science, perspectives of MDL begin with understandings of ‘fundamental literacy’ in science education (Norris & Phillips, 2003) and of ‘disciplinary literacy’ in broader literacy research (Fang & Schleppegrell, 2010; Moje, 2015; Shanahan & Shanahan, 2008). Fundamental literacy was used originally to refer to the reading and writing that is a necessary basis for science literacy, with the latter concept referring to the ‘knowledgeability, learning, and education’ of science (Norris & Phillips, 2003, p. 224). However, greater emphasis on authentic scientific practice has emphasized the interactive and dynamic relationship between these aspects (Yore, 2018). Disciplinary literacy has emerged as a research tradition through recognition of the increasingly specialized ways in which representations are deployed as students’ progress through the secondary science years. The competencies involved in disciplinary literacy are seen as distinct from everyday oral language and also from basic and generic literacies that are shared across curriculum areas (Shanahan & Shanahan, 2008). Foundational studies of verbal language in relation to fundamental and disciplinary literacy have provided important foundations for articulating the role of various modes and the possibilities inherent in these (Ainsworth, 1999), as well as for developing a metalanguage to talk about meaning making (Lemke, 1990; Veel, 1997).
1.2.1 Verbal language in science
Applied linguistic studies of written scientific research provide a range of perspectives on the construction of meaning and social context, with varying emphasis given to the weight of meaning carried by the context and discourse patterns of text. Rhetorical theorists (Bazerman, 1988; Latour & Woolgar, 2013) identified links between the language used in published research articles and the processes and practices of laboratory investigation, including the integration of persuasive and informative functions in writing. Bazerman (1988) argued that this integration was in response to contextual pressures on research scientists to both ‘create pictures of the immediate laboratory world’ and ‘say something new and persuasive’ (59). Perspectives from historical and socio-political contexts have allowed rhetorical scholars to theorize across many texts, including accounting for how Newton communicated empirical research in ways that ‘lent generality and universibility to his claims’ (Bazerman, 1988, p. 90). However, in grappling with issues of ‘context, agency, and the relationship between style and argument’ (Johnstone & Eisenhart, 2008, p. 5), limited attention has been given to the analysis of language to provide empirical evidence for how discourse constitutes and enacts context.
The social semiotic theory of systemic functional linguistics (hereafter, SFL) is widely used to interpret discourse patterns of texts in scientific research and classrooms (Halliday, 2004; Halliday & Martin, 1993; Lemke, 1990, 1998). In contrast to rhetorical theories, SFL researchers model context as semiotic systems that are realized through language. Language resources are understood to be distributed across different systems of meanings, which can by and large be mapped onto particular dimensions of context, thus providing the model with significant explanatory power. The level of context relating most closely with language is called register. Dimensions of register include the field, which relates to the topics and activities under investigation; the tenor, which relates to the relationship between composers of texts and their audiences; and the mode, which in written language refers to the ways a text is constructed to constitute the message. Foundational SFL research (Halliday & Martin, 1993; Lemke, 1990; Veel, 1997) identified a number of characteristic language structures which realize scientific English, including grammatical forms that are distinct from spoken language. The grammatical form, nominalization, for example, which is typically defined as a word ‘that has been transcategorized from, for instance, verb to noun class’ (Heyvaert, 2003, p. 67), has been recognized as critical resource for creating a technical field and for carrying forward the momentum of the argument’ in the written mode (Halliday, 1998, p. 202). Halliday (1998, 2004) also studied the variation of scientific writing over time and found that condensed noun groups became a significant feature of 20th-century scientific communication. This feature, which he described as ‘a general drift towards thinginess’ (Halliday, 1998, p. 211), has also been identified in science communication research as ‘convenient and even necessary devices for communicating technical information concisely’ (Gross, Harman & Reidy, 2002, p. 169).
Discourse patterns which have been identified in ‘adult science’ have been found to play a constitutive role in learning science, notwithstanding the influence of different processes involved in its recontextualization (Veel, 1997). Descriptions of genres which accomplish different social purposes have been particularly useful in examining recontextualized science practice in international educational policy (Fang, 2010; Schleppegrell, 2004; Tang & Putra, 2018). Genre has been understood as a more abstract level of context, which accounts for how choices for tenor, field and mode are mapped onto each other in unfolding discourse (Dreyfus, Humphrey, Martin & Mahboob, 2016). Martin further defines genre as ‘a staged, goal-oriented, purposeful activity in which speakers engage as members of our culture’ (Martin, 1985, p. 25). Genres for organizing and explaining events in school science have received significant attention in recognition of their contribution to ‘the creation of new knowledge to account for new phenomena’ (Tang & Putra, 2018, p. 570). In terms of literacy development, Unsworth (2001) has found that particular linguistic resources of written explanations in pedagogic materials can provide a systematic ‘textual bridge’ from common sense to scientific reasoning (p. 607). For example, grammatical shifts involving reformulations from verb structures which are more common in spoken language (e.g. compress) to noun structures (e.g. from ‘compress’ to ‘compression’) are important to build abstract concepts across explanations. By including structural phases to unpack and then repack the noun forms, a written explanation can progressively scaffold the development of knowledge. Much of the genre-based research in school contexts instigated to address challenges faced by diverse learners in writing and reading for the curriculum learning perspectives from sociology (Bernstein, 1990, 2000; Maton, 2013) have increasingly allowed SFL researchers to formulate principles for understanding the semiosis of discipline knowledge and how it develops and accumulates in terms of language and broader semiotic resources (Christie & Derewianka, 2008; Martin & Rose, 2008; Unsworth, 2000, 2001; Veel, 1997).
Descriptions of written genres and dimensions of register realized in verbal language provide an important base for exploring the contribution of verbal meanings to multimodal texts and in mapping the expansion of resources across the transition to senior school. Recent SFL studies have focussed on the construal of technical fields in a range of educational contexts (Maton, Martin & Doran, 2020) and have extended linguistic models to explain ‘syndromes of meaning’ involved in disciplinary knowledge building, particularly in physics (Doran, 2017, 2019) and biology (Hao, 2020; Hao & Humphrey, 2019). As we shall explore in the following sections, methods and conceptual frameworks developed through discourse-oriented research have also provided researchers with critical tools for investigating MDL in senior biology, chemistry and physics.
1.2.2 Multimodality in science
Extending research from written language to multimodality in school science has emerged from two related strands of research. Firstly, studies of talk in science classrooms by Lemke revealed how the specialized discourse of science develops through oral interactions amongst teachers and students, reflecting complex cultural and historical traditions of problem-solving (Lemke, 1990, 1998). Lemke’s (1998) further observation that ‘we never make meaning with language alone’ (p. 87) has inspired significant investigation of how classroom interactions integrate multiple semiotic modalities in construing scientific reasoning and knowledge building, including artefacts and embodied representation, symbols and maths modes and a range of visual forms (Doran, 2017; Hao & Hood, 2017; Kress & Ogborn, 1998; Lemke, 2004).
A related strand of multimodal research has emerged from studies of images in relation to language in research articles, textbooks or student writing. Social semiotic approaches to this research, which apply Kress and van Leeuwen’s (2006) descriptions of the grammar of visual design, foreground the context of communication and the ideology found within signs and attend to meanings made by individual modes, drawing on the concept of ‘affordance’ (Gibson, 1977) to investigate the ‘semiotic...