Confidence-Gated Semantic Retrieval for Indonesian Customer-Service Intent Classification
DOI:
https://doi.org/10.55123/jomlai.v5i3.9547Kata Kunci:
Abstention Mechanism, Confidence Calibration, Indonesian Language, Intent Classification, Sentence EmbeddingAbstrak
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.
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Hak Cipta (c) 2026 Marco Julius Andreas Bakkara, Mashelina Mashelina

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