Making the Invisible Visible: Indexicality, Iconicity, and Tacit Knowledge in Specialized Discourse

Keynote plenary - Research in Languages for Specific Purposes (LSP) has traditionally focused on the visible features of specialized language—its vocabulary, grammar, rhetorical structures, and genre conventions—both for teaching and for analysis. More recently, however, scholars have drawn increasing attention to the less visible, often implicit dimensions of specialized discourse. These include the ability to signal alignment with disciplinary norms, model accepted behavior, and understand unspoken expectations shared by experienced members of a professional or academic community (Dressen-Hammouda, 2014, 2023; Guillén-Galve & Bocanegra-Valle, 2021; Hyland, 2010; Lillis & Curry, 2010; Paltridge et al., 2016). Such tacit knowledge plays a key role in how writers and speakers are perceived as credible, fluent, or legitimate. Without access to it—whether when writing for publication, participating in academic tasks, or interacting in professional settings—language users may be at a disadvantage, regardless of whether they are native or non-native speakers. In response to this challenge, this talk proposes a framework for analyzing the implicit aspects of communication. It draws on the concepts of indexicality and iconicity (Peirce, 1955; Silverstein, 1976, 2003) to better understand how communicative legitimacy is constructed and interpreted in real-world contexts. Far from being marginal, these properties help anchor language in its context of use and make complex or abstract ideas more accessible through linguistic, visual, or gestural forms. After briefly introducing these concepts, I will present a five-part analytical framework developed in my forthcoming book (Dressen-Hammouda, 2025). Designed to analyze specialized language from a contextual perspective, the framework combines methods from diachronic analysis, linguistic ethnography, and genre studies. Applied to field writing in geology, it shows how features such as spatial and temporal deixis, evaluative expressions, and epistemic markers contribute to positioning the author as an expert. By making these inferential processes more visible, the framework reveals how writers construct their disciplinary identity, evaluate the value of their data, and situate their scientific work in both empirical and epistemic timeframes. In the final part of the talk, I will explore the implications of this approach for analyzing and teaching hybrid digital genres—such as video tutorials, video abstracts, or 3-Minute Thesis presentations (Carter-Thomas & Rowley-Jolivet, 2020; Dressen-Hammouda & Wigham, 2025; Liu, 2020; M. J. Luzón, 2019; Nezami Nav & Link, 2025). These multimodal genres likewise rely on indexical and iconic strategies to structure meaning and project discursive authority, with the added aim of making knowledge more accessible to a wider range of audiences (M.- J. Luzón, 2018; Myers, 2003). I will provide concrete examples of how this framework can be used pedagogically to help students better understand the hidden expectations of professional discourse. These observations will lead to practical suggestions for integrating the analysis of multimodal indexicality into LSP teaching.