Language as a tool for constructing knowledge and understanding in science 47 

Although it is widely accepted that one of the aims of education should be introducing ways in which children can use language for seeking, sharing and constructing knowledge, observational studies of classroom life reveal that this induction is rarely carried out in any systematic way (Mercer, Wegerif, & Dawes, 1995). According to researchers (Barnes & Todd, 1995; Edwards & Mercer, 1987; Sheeran & Barnes, 1991), learners’ conversational interactions are often stifled due to the lack of guidance and explicit, shared understanding of the purpose of various classroom activities, and the criteria by which they are being assessed by their educators. Furthermore, learners are often confused, unfocused and unproductive in their use of language (Mercer, et al., 1995). Fullerton (1995), however, suggests that through science talk, reading and writing, learners are encouraged to make sense of their thinking and to bridge new concepts and clarify thought while also developing their scientific vocabulary. Accordingly, the development of science discourses through content-based language instruction has been promoted as an effective teaching and learning approach for all learners, but especially those who are learning though a medium of language which is not their own (Gianeli, 1991). Deborah Short describes this approach (1991, p. 1) as follows:

The integration of language and content involves the incorporation of content material into language classes, as well as the modification of language and materials in order to provide for comprehensible input to LEP (Limited English Proficiency) students in content classes. The former is often referred to as content-based language instruction; the latter can be referred to as language-sensitive content instruction. An integrated approach bridges the gap that often separates the language and content classrooms.

Douglas Barnes’ (1975) seminal work From Communication to Curriculum introduced that there are specific kinds of ‘talk’ that occur in the classrooms and acknowledges the social aspects of learning and sharing information. His term ‘exploratory

talk’ distinguished the category of language used by learners when talking to their peers as opposed to the language or ‘presentational talk’ used when talking to the teacher (Edwards & Jones, 2001). Mercer’s (1996) later analysis of exploratory talk represents a scaffolded model of learning whereby learners explain and justify their decisions to one another through

disputational, cumulative and exploratory talk. Disputational and cumulative talk are

characterised by disagreements between learners and the exchanges are brief, consist of assertions, and counter assertions (disputational) and by repetitions, confirmations and elaborations which build and reinforce each other’s ideas, but are generally uncritical of what their peers say (cumulative), exploratory talk occurs when learners are engaged in critical and constructive discussion. Learners’ ideas are discussed, challenged and alternative viewpoints are offered for consideration.

When learners are engaged in exploratory talk, decision-making is a collective process through which learners can come to a consensus about the idea. In comparison to the two previous forms of talk, in exploratory talk, knowledge is made public and therefore learners become accountable for their ideas, and reasoning becomes a more important part of the talk while progress emerges from the eventual joint agreement reached (Mercer, 1996). In this process, learners’ contributions and ideas are accepted, challenged, negotiated and the group is held accountable for their assertions. Researches assert that this socio-linguistic process of exploratory talk improves group and individual reasoning in children (Webb & Treagust, 2006; Wegerif, Mercer, & Dawes, 1999).

The issue of exploratory talk is especially important in the South African context as research suggests that there is little evidence of meaningful discussion in the classrooms of schools, which were previously disadvantaged under the system of Apartheid and where both teachers and learners officially operate in their second language (Taylor & Vinjevold, 1999).

Under the Apartheid education system, the authoritarian teaching and learning environment was characterised by rote propositions that brooked no analysis or critique (Webb, 2008) and generally followed the teacher-led triadic exchange of initiation-response-evaluation, IRE (Edwards & Mercer, 1987; Mehan, 1979; Mortimer & Scott, 2003; Sinclair & Coulthard, 1975). IRE commonly refers to the teacher posing a close-ended or lower-order thinking question, to which student replies with an answer and the teacher offers feedback in a one word, or shortened response. This type of classroom environment fostered little discussion and would explain why international research has found that learners have a vague understanding of the purpose behind their classroom activities and so are often perplexed, unfocused and unproductive in their use of language (Barnes & Todd, 1995; Edwards & Mercer, 1987; Sheeran & Barnes, 1991). Educators employing IRE in their classrooms do so as a way of controlling the classroom and avoiding situations where the teacher may not know the answer (Dillon, 1994; Edwards & Mercer, 1987). This type of ‘talk’ poses challenges to the nature of science, as learners may perceive science knowledge as fixed and without room for questioning, discovery or “incorrect” answers (Lemke, 1990).

Through compromise and cooperation, learning occurs when the participants, either learner/learner or learner/teacher, negotiate meaning and a mutuality of meaning or a new hybrid meaning is constructed (Edwards & Jones, 2001). Osborne and Wittrock (1993) identified this construction of meaning through the negotiation of prior knowledge and sensory output as generative learning. This view respects the learners’ experiences and epistemology through multiple discourses (Bhabha, 1994) and provides opportunity for authentic learning to occur. Edwards and Jones (2001) suggest that educators are compelled to accept learners’ understandings even if they are not in line with conventional scientific authority, yet educators still have the responsibility of assisting learners in organising and

learner (Webb & Glover, 2004). In exploratory talk, this may mean directing learners’ attention to the topics of discussion and drawing on learners’ current knowledge to construct personal meanings and evaluating that meaning (Webb & Glover, 2004).

Through the process of utilising prior knowledge, exploratory talk and evaluation of the discussion, learners must be reasonable both in giving statements and being open and responsive to others. This ‘communicative rationality’ allows learners’ reasoning to be made visible and publicly accountable through the discussion of alternatives (England, et al., 2007). The use of discussion also provides a platform for learners to ask questions for clarification, curiosity, explanations, and in order to challenge ideas, as well as to produce an investigable question, or what some researchers describe as a ‘profitable question’ (England, et al., 2007). Profitable or investigable questions are a natural progression in the process of inquiry and can be used to test ideas in the form of authentic scientific investigations.