“…The development of scientific explanation based on theories and models to account for a specific phenomenon or situation is a central part of science (National Research Council, 2012; Osborne & Patterson, 2011). Several studies investigating the nature of scientific explanation have been carried out from a range of perspectives, including the philosophy of science (e.g., Braaten & Windschitl, 2011; de Andrade et al, 2019; Tang, 2016), linguistic and genre theories (e.g., Fang et al, 2010; Seah, 2015; Unsworth, 2001), mechanistic reasoning (e.g., Moreira et al, 2019; Russ et al, 2008; Talanquer, 2010), and textbook analysis (e.g., Dimopoulos et al, 2005; Velentzas & Halkia, 2018). However, most of these accounts tend to foreground the verbal (written or spoken) explanations without analyzing the characteristics of diagrams that are central rather than auxiliary to the construction of explanation.…”