This poster reports final results from a 2025 Panasonic Education Foundation–funded longitudinal study examining the sustained impact of Arizona AI, a researcher-developed AI-mediated automated written corrective feedback (AWCF) tool on English paragraph writing among 120, 2nd-grade Japanese high school students. The study represents the conclusion of interim findings previously presented at the 2025 JALT International Conference in Tokyo, extending earlier analyses to a full instructional cycle.

Using repeated baseline–midline–endline measures, the study analyzed changes in human-rated writing performance across multiple rubric categories, including structure, grammar, transitions, and sentence complexity. Results show steady improvement over time, with the strongest gains occurring when AI feedback was embedded within a structured classroom workflow rather than used as a stand-alone intervention.

The findings speak directly to the conference theme “Prevail or Fail?” by identifying a central risk in CALL adoption: AI feedback systems that succeed technically but fail pedagogically when learner scaffolding and feedback literacy are insufficient. Implications are discussed for sustainable AI integration in EFL writing instruction, rubric-aligned prompt design, and teacher mediation strategies that enable AI feedback to prevail beyond novelty effects.