This meta-analysis synthesizes evidence on the effects of ChatGPT-assisted instruction on English writing in Korean EFL contexts. A systematic search in RISS yielded 401 records; after screening under PRISMA procedures, 12 studies reporting writing outcomes were included and analyzed. Effect sizes were computed as Hedges’ g and pooled using random-effects models. The random-effects mean indicated a medium-tolarge improvement in writing (g = 0.6867). Mixed-effects subgroup analyses detected no statistically significant differences by experimental design (pre-experimental vs. quasiexperimental), educational level (tertiary vs. secondary), or region (metropolitan vs. others). Meta-regression trends for duration (weeks, positive) and weekly intensity (sessions/week, negative) were suggestive but not statistically significant. Overall, ChatGPT-supported writing instruction yields meaningful gains and shows consistent effects at both secondary and tertiary levels; in practice, it is well suited to complement teacher feedback. Future studies should expand samples in secondary and nonmetropolitan settings and employ stronger designs to clarify how duration and intensity shape outcomes.

1. INTRODUCTION
2. LITERATURE REVIEW
3. METHODOLOGY
    3.1. Literature Search
    3.2. Instruments
    3.3. Analysis
4. RESULTS AND DISCUSSION
    4.1. Coding Results and Individual Effect Sizes
    4.2. Publication Bias
    4.3. Homogeneity and Mean Effect Size
    4.4. Effect Sizes by Moderating Variables
5. CONCLUSION AND IMPLICATIONS
REFERENCES
APPENDIX

• Je-Young Lee(Professor, Department of English Education, Jeonju University, 303 Cheonjam-ro, Wansan-gu, Jeonju-si, Jeollabuk-do 55069, Korea)