Has the prose quality of science textbook improved over the past decade? A linguistic perspective

Abstract

Textbooks are a central pedagogical resource for science teachers. As such, they have been a subject of enduring interest in science education research, with many questioning whether their quality has improved over the past decades. In this paper, we examined the prose quality of an expository text on coral reefs in seven successive editions of one popular environmental science textbook. Specifically, using tools from systemic functional linguistics, we analyzed two discursive aspects that impact the comprehensibility of the texts - how causation is construed and how information is structured. Our analyses reveal that the prose quality of the texts on coral reefs has improved, regressed, or remained the same. In the area of causation, cause-effect relationships are construed in increasingly implicit ways, with causes and effects consistently constructed as grammatical abstractions that bury human or social agencies. In the area of information flow, semantic leaps and semantic ambiguities are reduced across the sample texts analyzed, which places fewer text processing demands on the reader. Our study suggests that writing a perfectly considerate text is a tall task and that micro-linguistic analysis can illuminate the comprehension challenges that school textbooks present to students and inform efforts to improve students' science literacy.