["Journal of Computer Assisted Learning, Volume 42, Issue 5, October 2026. ", "\nABSTRACT\n\nBackground\nGenerative artificial intelligence text‐to‐image tools are increasingly used in design education, but evidence is limited on whether structured classroom integration improves expert‐rated creativity outcomes while controlling homogenisation. The objective was to test whether a Studio GenAI Creativity Enhancement Model (S GCEM) workflow using Midjourney improves expert‐rated illustration creativity versus a conventional non‐generative workflow and whether process metrics explain observed differences.\n\n\nMethods\nA parallel‐group, two‐section quasi‐experiment was conducted in an undergraduate illustration design studio. Students in the intervention section used S GCEM with Midjourney for early‐stage ideation only, mandatory prompt and version logs, and identical critique milestones to the control section (manual brainstorming, thumbnail sketching, non‐generative references). The analytic sample was n = 162 (S GCEM n = 82; control n = 80). Baseline and final artefacts were scored on 1–5 rubrics for originality, appropriateness, and elaboration. Ideation breadth and iteration depth were derived from logs. Analyses used analysis of covariance and regression.\n\n\nResults\nFinal Product Creativity was higher under S GCEM than control after baseline adjustment, F(1,159) = 9.000, p = 0.003, partial η2 = 0.053. Final Originality differed by condition, F(1,159) = 6.000, p = 0.015, partial η2 = 0.036; Appropriateness, F(1,159) = 4.000, p = 0.047, partial η2 = 0.024; and Elaboration, F(1,159) = 9.000, p = 0.003, partial η2 = 0.054. Ideation breadth increased under S GCEM, B = 0.95, t = 4.13, p = 0.001, 95% CI 0.50–1.40, and iteration depth increased, B = 0.70, t = 3.50, p = 0.001, 95% CI 0.30–1.10. Homogenisation was lower under S GCEM, U = 2500, z = −3.05, p = 0.002, r = 0.24.\n\n\nConclusion\nA structured Midjourney‐supported ideation workflow improved expert‐rated illustration creativity while increasing documented ideation activity and reducing homogenisation indicators.\n\n"]