Abstract
Writing proficiency remains an essential academic competency; however, many senior high school students continue to experience difficulties in writing, particularly in grammar, organization, and idea development, which often affect the quality of their written outputs. In this context, artificial intelligence (AI) writing tools have become increasingly integrated into writing instruction. This study aimed to assess the impact of AI-assisted writing tool utilization on the writing proficiency of senior high school students. The study employed a quantitative quasi-experimental research design. Using quota sampling, a total of 60 Grade 11 students from the Arts, Social Sciences, and Humanities (ASSH) strand of a private Catholic institution were selected and were equally divided into two groups, the experimental and control group. Data were gathered through a pretest–posttest writing assessment evaluated using an analytical scoring rubric. Descriptive and inferential statistical analyses were employed to examine differences in writing proficiency before and after the intervention. The results revealed that both groups had comparable pretest scores; however, the experimental group demonstrated greater improvement after the intervention. The experimental group achieved a higher post-test mean score (M = 82.04) compared to the control group (M = 77.81), and statistical analysis indicated a significant difference between the groups. These findings suggest that AI-assisted writing tools can significantly enhance the writing proficiency of senior high school students when used as supplementary instructional support. It recommends the integration of AI-assisted writing tools into writing instruction through appropriate policies, teacher training, and ethical guidelines. Future studies should explore longitudinal impacts of AI-assisted writing tools on students’ learning and academic development.