"These data support the provocative view that...": evaluation in medical academic posters.

In the hard sciences, posters have rapidly become a major format for scientific academic communication. In order to facilitate knowledge dissemination and academic discussione, medical posters, in particular, are uploaded on the Net after the conference where they have been presented. The Net, therefore, appeas to be the place where medical knowledge is mediated amongst specialists. Yet, in other disciplines, posters are commonly regarded as less prestigious than research papers, probably because of the predominance of visual elements in it. In posters, due to space/length constraints, generalised and theoretical claims tend to be 'topicalised', rather than discussed. One of the most powerful ways of thematizing attitudinal meanings and present an explicit statement of evaluation academic discourse is by means of that-structures. This research will, therefore, investigate how the evaluation is conveyed through that-structures, i.e. those complement clauses embedded in a superordinate one (the matrix clause) to complete its construction and project the writer’s attitudes about something. The study has been carried out using WMatrix (at http://ucrel.lancs.ac.uk/wmatrix3.html) and is based on the analysis of the verbal elements contained in a corpus of 562 medical posters (775,609 tokens) presented at international conferences and uploaded on the Web. In particular, the investigation tries not only to detect what type of verbs (whether cognitive, discursive or research ones), but, above all, to understand why they are used across the Introduction-Methods-Results-Discussion sections of posters and whether their choice depends on the author's awareness posters will be uploaded on the Net. Although such analysis certainly has some limitations, and needs to be triangulated, it may offer new insights of the genre of posters distributed via the Web, given the lack of applied linguistic research on posters.