Confidence-Gated Indonesian Grammatical Error Correction Under Synthetic-to-Authentic Domain Shift

Indonesian grammatical error correction (GEC) requires decisions about when to apply a proposed edit under synthetic-to-authentic domain shift. We evaluate a selective correction framework using a reconstructed, fully executable experiment. An audit of 1,955 authentic records removed 36 incomplete pairs, 14 duplicates, 45 string identities, and five additional to-ken identities, leaving 1,855 pairs. Exact-text groups were partitioned into 1,297 training, 280 validation, and 278 test pairs. Synthetic priors were learned from 200,000 public development pairs. A cross-fitted logistic ranker combined synthetic mappings, authentic templates, spelling retrieval, and local language-model evidence. Thresholds were chosen on validation data under joint degradation and overcorrection budgets. At the 2% budget, the gate accepted five source edits, four correct: precision 80.00%, F0.5 4.03, coverage 1.80%, and word-error reduction 0.88%. No test source was degraded, but one of 278 correct-target controls changed. The precision interval was 37.55–96.38%. Removing the synthetic channel reduced available gold candidates from 110 to 109 and accepted true positives from four to three. Replacing the language-model feature with frozen IndoBERT produced 66.67% precision at 2.16% cover-age, with one degraded source and one changed control. The results support restrictive authorization on this corpus, show limited unique synthetic contribution, and expose a substantial candidate-recall bottleneck. They do not establish broad correction ability or readiness for educational deployment.

@article{Suroso2026,
  title     = {Confidence-Gated Indonesian Grammatical Error Correction Under Synthetic-to-Authentic Domain Shift},
  journal   = {International Journal of Advanced Computer Science and Applications},
  volume    = {17},
  number    = {9},
  year      = {2026},
  publisher = {The Science and Information Organization},
  author    = {Eko Suroso and Onok Yayang Pamungkas and Laily Nurlina and Sudiyono and Jimat Susilo and Eko Priyanto and Hera Septriana},
  doi       = {10.14569/IJACSA.2026.0170927},
  url       = {https://doi.org/10.14569/IJACSA.2026.0170927}
}