Confidence-Gated Semantic Retrieval for Indonesian Customer-Service Intent Classification

Penulis

  • Marco Julius Andreas Bakkara Universitas Sumatera Utara
  • Mashelina Mashelina Universitas Sumatera Utara

DOI:

https://doi.org/10.55123/jomlai.v5i3.9547

Kata Kunci:

Abstention Mechanism, Confidence Calibration, Indonesian Language, Intent Classification, Sentence Embedding

Abstrak

Customer-service chatbots deployed in low-resource languages must decide not only which intent a message expresses but also when to decline answering. This study evaluated a confidence-gated retrieval architecture for Indonesian intent classification in which a deterministic keyword layer, a multilingual sentence encoder, and an explicit abstention rule were combined. A corpus of twenty-two intents containing three thousand nine hundred sixty training patterns and one thousand fifty-six held-out test patterns was constructed, covering commerce enquiries, complaint handling, and instrumentation engineering questions. Two retrieval backends were compared under identical decision logic: a lexical backend that fused word and character term weighting with a naive Bayes component, and a semantic backend built on multilingual sentence embeddings. The semantic backend reached an accuracy of 82.67 percent and a macro-averaged F-measure of 83.04 percent, exceeding the lexical backend by 11.74 and 12.31 percentage points, at a mean response latency of 30.66 milliseconds on a single processor. Raising the confidence threshold increased selective accuracy from 71.06 to 82.82 percent while coverage fell to 61.17 percent, which quantified the price of caution. Of 100 balanced out-of-scope probes, 93 were rejected (93.00 percent). The deterministic layer resolved just over half of the queries and carried the higher accuracy of the two decision paths.

Biografi Penulis

Mashelina Mashelina, Universitas Sumatera Utara

S2, Lecturer, Corresponding.

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Diterbitkan

2026-09-29

Cara Mengutip

Marco Julius Andreas Bakkara, & Mashelina, M. (2026). Confidence-Gated Semantic Retrieval for Indonesian Customer-Service Intent Classification. JOMLAI: Journal of Machine Learning and Artificial Intelligence, 5(3), 142–152. https://doi.org/10.55123/jomlai.v5i3.9547

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