room norms that emphasize responsibility, tolerance, and the construction of arguments based on theory and evidence. Without teacher intervention, students do not spontaneously adopt either the general social norms or the specific scientific epistemic grounds for conducting productive dialogic discourse (Osborne et al., 2001). Herrenkhol and Guerra (1998) examined the effectiveness of directly teaching specific audience roles for encouraging productive scientific argumentation in the elementary grades. As small teams of fourth graders reported the results of their investigations to the whole class, the audience members were asked to assume responsibility for checking on the presenters by taking one of the following roles: (1) asking clarification questions about predictions and theories, (2) challenging claims about their results, or (3) raising questions about the relationships among their predictions, theories, and results. When students were assigned these roles, the discourse patterns in the classroom showed increased negotiation of shared understanding, monitoring of comprehension, challenges to others’ perspectives, and coordination of theories and evidence.
In addition to its emphasis on discourse patterns, such as forms of scientific argument, science is also associated with a style of language use that does not match everyday kinds of talk. Specialized kinds of activities, like science, are often associated with specialized forms of language. Science, mathematics—and, for that matter, ham radio and drug selling—are activities conducted by organized groups of people who tend to communicate in particular linguistic styles, sometimes called “registers” (Halliday, 1988). Scientific language tends to emphasize the passive voice, especially in its textual forms, and as a result, people are rarely present in science talk or text, as either agents or participants (Lemke, 1990). Scientific language often features abstract nouns that are derived from verbs (e.g., “the revolution of the earth around the sun”) and technical terms that have different meanings than in everyday use (e.g., “force,” “energy”). Narrative and dramatic accounts are avoided, as are colloquial expressions and ambiguous words, such as pronouns with unclear referents. The impression lent by these features of scientific style is that the text is communicating a simple and veridical description of the way the world actually is—a straightforward reading of the book of nature (Olson, 1994), rather than a complex social activity conducted by humans. For these reasons, Lemke (1990) suggests that teachers work deliberately to provide opportunities for students to practice at “talking science.” This goal may be accomplished through a variety of means, such as teaching students how to combine scientific terms in complex sentences, discussing their commonsense theories on science topics, teaching students the genres of science writing, and bridging colloquial and scientific language, for example, by asking students to translate back and forth between scientific and colloquial statements or questions.