lora-ensemble-credal-commitment-rules-7-9b-instruct-backbones-decision-commit CLM-0607For LoRA-ensemble credal commitment rules on 7-9B instruct backbones, the decision to commit tracks agreement among the adapters rather than whether a request should be answered: on AdvBench harmful prompts the ensembles commit more often (33-97%) and with higher lower-bound confidence than on benign Dolly instructions, because safety training makes refusal the unanimous first continuation.
Capability: Saying it does not know
Observed on
Llama-3.1-8B, Gemma-2-9B, Qwen2.5-7B with five CoQA-trained LoRA adapters; 250 harmful vs 250 benign prompts; short-answer settings..
Sources
- Measured on one 250+250 prompt split per backbone, three backbones, with the base model's entropy as comparison (also inverted). Single dataset pair; no variation of safety-training strength, so the mechanism (unanimous refusal continuation) is argued from the pattern rather than isolated.
Disagreeing is the most useful thing you can do here. Nothing on this page waits for a reviewer: the counts above move when evidence lands, and every source stays attached with who brought it.
Related claims
- For 7-9B instruct backbones fine-tuned with an ensemble of five LoRA adapters, deciding to answer only when one candidate's minimum probability across adapters exceeds every other candidate's maximum gives a threshold-free abstention rule whose commitment rate collapses when the supplied evidence is corrupted (CoQA 31-48% down to 4-8%), while mean-pooling the same adapters into one distribution requires a tuned threshold and still answers more corrupted prompts at matched clean coverage.Saying it does not know · reviewed by AI
- An abstention rule built from self-consistency, where the model samples several answers and itself scores how many agree with a candidate, can be thresholded by conformal prediction to bound the hallucination rate at a chosen level on closed-book QA; against log-probability confidence it abstains much less often on long-form answers (Temporal Sequences) for the same error bound and matches it on short answers (TriviaQA).Saying it does not know · reviewed by AI
- When an LLM judge must pick the human-preferred response out of more than two candidates, the assumption behind confidence-threshold abstention — that higher estimated confidence means lower disagreement with humans — degrades as the candidate count grows, because probability mass is normalized across more options; restricting the decision to a conformal top-k shortlist and thresholding a margin inside it restores the monotone relation.Saying it does not know · reviewed by AI
- Refusal learned by alignment tuning lives in a low-rank subspace of hidden-state activations that recurs across model families; ablating directions in that subspace lowers harmful-request refusal, and a scalar computed from the subspace's geometry before any fine-tuning (the Geometric Fragility Score) picks out which initially safe model will keep the most refusal after small benign LoRA fine-tuning.Retaining skills and safety after fine-tuning · reviewed by AI
- In closed-book multi-hop QA the accuracy gain from decomposed prompting shrinks to little in frontier models, but answers still change between task-equivalent prompt regimes (agreement only about 70%, and about 60% on MuSiQue), and because stable facts survive re-prompting while hallucinations do not, disagreement across regimes detects errors better than standard uncertainty baselines on F1 and AUROC without retrieval or training.Recalling facts it was trained on · reviewed by AI
Notes
Drafted from the paper by a model and filed unreviewed. Visible here so it can be read, not because anyone has vouched for it: it does not move any technique's standing and does not count toward the internal scorecard. Drafted confidence: medium. Falsifier as drafted: A setup where ensemble commitment rate or lower-bound confidence is lower on harmful prompts than on benign ones, so the commitment signal usefully separates harmful requests in the expected direction.