From tool to scaffold: structured human–AI collaboration and its effects on academic writing and digital critical thinking among Saudi EFL learners

This mixed-methods quasi-experimental study examined whether pedagogically structured, AI-supported writing instruction is associated with improvements in EFL academic writing performance and digital critical thinking/AI literacy among Saudi university students. Fifty-three undergraduates were assigned by intact classes to an experimental group ( n = 31) or a control group ( n = 22). Over 10–11 weeks, the experimental group practiced guided human–AI collaboration workflows—encompassing problem framing and prompt design, iterative drafting, revision cycles, verification of claims and citations, and responsible-use regulation—using a generative AI assistant and a language-feedback tool, while the control group completed the same syllabus without systematic AI integration. Both groups completed parallel pretest/posttest writing tasks (0–20 scale) and the Digital Critical Thinking Scale (DCTS; 20 items; 20–100; α = 0.97 pretest, α = 0.99 posttest). At posttest, the experimental group scored significantly higher on writing proficiency ( M = 15.23 vs. 11.91; large effect) and DCTS total ( M = 89.84 vs. 56.18; very large effect). Writing proficiency and DCTS were strongly associated at both posttest and in gain scores. Thematic analysis of experimental-group reflections revealed that students employed AI primarily as a planning and revision scaffold, while simultaneously enacting verification routines and articulating ethical self-regulation strategies. This study contributes context-specific empirical evidence demonstrating that agency-preserving, critically guided AI integration can simultaneously advance writing quality and digital critical thinking in EFL higher education contexts where such paired outcome evidence remains scarce. However, results should be interpreted as preliminary and institution-specific, given the modest sample, intact-class assignment, and single-institution context, which limit generalizability to other EFL populations and settings.