How true is scientific discourse? A comparative study of epistemicity in on-page and on-screen media

This chapter examines the visual-cum-verbal encoding of epistemic modality in scientific discourse by comparing traditional research articles with infographic synopses. Words and visuals use different strategies that co-operate in the validation and dissemination of evidence-based knowledge: while the former symbolise empirical data through written, abstract, discontinuous and temporal resources, the latter shape it into sensorial, contiguous and spatial patterns that facilitate cognitive functions such as quantification, recognition and comparison. Within the framework of Systemic Functional Grammar, and incorporating multimodal analysis and medical semiotics, I compare cross-semiotic epistemicity in on-page vs. on-screen media, looking at how differently words and graphics can codify possibility, probability, necessity and certainty, and at the impact of multi-literacy in epistemological discourse.