Since the rhetoric of science emerged as a field of inquiry, there have been at least two possible areas for investigation: the study of how science is used in public discourse and the study of how scientists argue and persuade within their professional communities. But, as the field developed, research in the latter area outpaced that in the former, leaving 'the professional discourse of scientists ... as the "prototypical" form of text studied in the [rhetoric of science]' (Ceccarelli, 2001, pp. 314-315). Often, rhetorical work in the first area has concerned itself with how scientific information is changed or distorted as it is accommodated for the general audience (e.g., Fahnestock, 1986) and has thus tended to reify the notion that scientific and public discourse occurs in two separate spheres (Locke, 2002). This traditional view of science communication, often called the deficit model, holds that public or social knowledge is external to, and inferior to, scientific knowledge, and that communication between these spheres is unidirectional, from science to the public (Myers, 2003).
However, as Beacco, Claudel, Doury, Petit, and Reboul-Toure (2002) argue, scientific discourse is not limited to popularizations or accommodations from scientists to the general public via journalist mediators. Instead, scientific discourse is part of a great deal of public discourse, both in the news media and in everyday talk. This overlap is apparent in news reports and everyday talk about topics ranging from health issues, such as rates of cancer and prevention of HIV/AIDS, to technological issues, such as energy policy and genetic engineering, to social issues such as whether there are gender differences in brain structure and whether homosexuality is a heritable trait (and the implications of such research on debates about civil rights). Although science is frequently implicated in public discourse, it often requires, as Darsey (2002) notes, 'the public to accept ]scientific] explanations that are non-obvious, even counter-intuitive' (p. 471). Although such communication has not replaced more traditional accommodations of expert discourse for lay audiences (Moirand, 2003), the increasingly important role of science in communication about controversial political issues has problematized the division between technical and public spheres (Myers, 2003). For example, in many science stories in the news media, the role of expert is no longer limited to the scientist, but can also include citizens or advocates (Beacco et al., 2002; Conrad, 1999).
In this paper, I show how theoretical and methodological insights from discourse analysis and rhetorical theory can be applied to public communication, specifically news discourse, about controversial science. In particular, I discuss how studies of the structure of news discourse map onto Perelman and Olbrechts-Tyteca's notion of Presence as well as their discussion of selection and presentation of data in argumentative discourse. I then review recent discourse studies of news discourse about controversial science. I show how the linguistic choices that discourse analysts orient toward in studies of scientific discourse can be described as appeals to scientific ethos motivated by topoi derived from an idealized vision of science. Finally, I apply this framework to a set of news texts and press releases reporting and responding to a controversial study on 'reparative therapy' for homosexuality.
This analysis shows how the structure and conventions of news discourse may accomplish the rhetorical goal of demarcation (of good science from bad). This demarcation, or boundary-work, is accomplished both at the level of framing, and at the level of specific 'micro-rhetorical' linguistic choices (Johnstone, 2002) that can be made throughout a news text. In other words, the detailed textual analysis reveals some of the ways in which rhetorical strategy and audience design …