Debates on the use of global languages as medium of instruction in schools have largely centred on identifying policies and practices that improve learning or social justice concerns regarding distribution of the benefits of education. Thinking in terms of education for sustainable development focuses attention on the utility of learning. Questions of language in education need to consider not just the capacity to acquire and demonstrate knowledge but also the capacity to develop, adapt, apply, share, debate and grow knowledge across and within communities. These questions are explored with reference to an initiative by a group of teacher educators in Tanzania, to develop a pedagogy for supporting language learning within and through secondary school science education.
Secondary school students need to acquire both ‘powerful knowledge’ (Young, 2009), articulated in writing through formal scientific language, and also ‘scientific literacy’ (Aikenhead, 2007), scientific knowledge that is understood and applied every day and connects with common sense knowledge. These dual objectives for science learning are mirrored in dialogue in secondary school science classrooms, which moves back and forth between the formal language of science and the informal language of thinking and talking. In Tanzanian secondary school classrooms, all learners and teachers are fluent in an African language, Kiswahili, which is a national language and the medium of instruction in government primary schools. Secondary education, however, is only available in English. This means that classroom dialogue switches between formal scientific English and informal or conversational Kiswahili. Hence, a contextually contingent (Vavrus, 2009) pedagogy is required, a theory and practice of teaching developed within Tanzania. In parallel to how science is learned, this also is a two way process of developing formal vocabulary of pedagogy, that codifies and is reinterpreted back into the more informal language of professional practice.
