Engagement Resources across Three Medical EAP Textbooks: A Corpus-Based Comparative Study

Medical English for Academic Purposes (EAP) textbooks do more than present disciplinary content; they also model how claims are asserted, qualified, and attributed. This study provides a descriptive corpus comparison of engagement resources in three medical EAP textbooks: two produced by Persian-speaking author teams and one by an English-speaking author. Reading passages totaling approximately 5,200 words per book (approximately 15,600 words overall) were randomly selected across textbook units and coded using the engagement subsystem of Appraisal theory. A second trained coder independently annotated 20% of the corpus (κ = .94), and the primary analyst recoded 20% after a four-week interval (κ = .91). Because the three textbooks, rather than individual clauses, constituted the comparative cases, the findings were interpreted descriptively through raw frequencies, within-text percentages, normalized rates, and contextualized examples. Monoglossic resources constituted 64.8% of 1,378 coded instances, whereas heteroglossic resources constituted 35.2%. Within heterogloss, expansion predominated (78.1%), principally through entertain and probabilize, while contraction was realized mainly through disclaim. Attribution relied more on acknowledge than hearsay, and no distance instances were identified. The three books thus shared an authoritative instructional orientation but differed in the density and internal composition of their engagement resources. These differences are treated as properties of the sampled texts and cannot be attributed uniquely to writer language background.