The argument from the shared-representation root cause of shallow unlearning
The argument
Standard unlearning methods are undone by brief fine-tuning (brief fine-tuning restores knowledge removed by RMU and gradient ascent). The proposed cause is that these methods alter representations shared with retained data, which fine-tuning recovers. A method that edits only forget-specific representations (RepSelect, which removes the top principal components of the gradients before each update) is reported to cut post-relearning answer probability 4 to 40 times more than five baselines, across five datasets and three model families. So robustness depends on selectivity, and post-hoc editing that is not selective will not be robust.
Does it work?
- Does it follow?
- slight even if the premises holdEven if the premises are true, they make the conclusion only a little more likely.constitution →
- Do the premises hold?
- 1 supported1 not separately assessed
Granting its premises, the argument shows that selectivity makes in-place unlearning much more robust, and that non-selective edits to shared representations are a cause of shallowness. That is evidence of sufficiency and benefit, not necessity: a large gain over five baselines does not rule out other routes to robustness. So it bears only slightly on the claim as worded, though it strongly supports a narrower thesis about weight-editing methods. It rests on linked claim, which is not yet assessed and comes from one preprint, and on linked claim, which is supported.
Premises
- UnassessedNo current assessment. Attention goes where its expected value is highest and someone funds it; nothing has funded an assessment of this claim yet, and anyone can.constitution →LLM unlearning is reversible and disruptive because methods alter representations shared with retained data and recoverable by fine-tuning.
- SupportedThe evidence favors the claim, but the examination is incomplete or the evidence is indirect.constitution →Brief fine-tuning restores knowledge that standard LLM unlearning methods such as RMU and gradient ascent were applied to remove.
Where it is made
Passages where sources make, criticize or mention this argument. They record where it appears, not how strong it is, and none has precedence over another.
No source is recorded as making it.