Source

Koh and Liang (2017), LIT-403 — the method and the dataset-repair experiment. Pruthi et al. (2020), LIT-400 — the same recommendation from a different estimator, with the mechanism. Bae et al. (2022), LIT-402 — the correction to what an influence estimate measures, in source: because without it this practice rests on an explanation the field abandoned.

The instruction

Score each training example against itself: the influence of the point on its own loss. Sort descending. Inspect from the top.

The obvious alternative is to sort by training loss — the examples the model gets wrong. It works less well, and the reason it works less well is the interesting part.

Why self-influence separates errors and loss does not

A mislabelled example is a strong proponent of itself. Strong because it is an outlier: nothing else in the corpus supports its label, so the model has to move specifically for it. A proponent because the movement does reduce its loss — with respect to the wrong label it carries.

High training loss picks up two populations that self-influence separates: the genuinely mislabelled, and the genuinely hard. Both have high loss. Only the first is an example the model had to be dragged toward on its own.

On Enron1 spam with 10% of labels flipped, inspecting in influence order repaired the dataset after checking fewer points than the highest-loss ordering or random inspection, over 40 repeats, with no access to test data. On CIFAR-10 with 10% of labels changed to the highest-scoring incorrect class, TracIn’s self-influence recovered more of the corruption at a fixed inspection budget than influence functions or representer points.

The explanation under it was replaced and the practice was not

THEORY-017 — the account this method was derived from, that an influence estimate approximates what would happen if you removed the point and retrained — is Rejected for neural networks. THEORY-018 replaces it: what the estimate tracks is the proximal Bregman response function.

That would be a reason to withdraw this practice if it needed the counterfactual. It does not. It needs an ordering over training points, and LIT-402 says explicitly that the PBRF supports the use cases that motivated influence functions, naming mislabelled-example detection as one. The practice is filed knowing which of its foundations moved.

Conditions

Every evaluation in the record is synthetic label corruption at classification scale. Labels flipped at random, or to the most confusable class — a clean, adversarial, well-posed kind of error. Whether self-influence separates natural annotation noise, ambiguity or systematic annotator bias is untested here, and those are the errors real corpora have.

Nothing here is at language-model scale. Enron1 is 4,147 documents; CIFAR-10 is 50,000 images. LIT-401 shows the machinery reaches 52B parameters, and nobody has pointed it at corpus cleaning.

Pick the estimator by what you have, not by which paper you prefer. TracIn needs saved checkpoints, per-example gradients and a loss, and no curvature. Influence functions need only the final model, and an inverse-Hessian approximation good enough to be worth the trouble — EK-FAC, at scale. Which constraint binds is usually decided by how the training was operated rather than by a judgement about methods.

Self-influence is the cheap diagonal, and cheapness is the argument. The full influence matrix answers far more and costs far more; this practice needs one number per training example, which is why it is the use case that has survived every reinterpretation of what the number means.

Known implementations

  • TracIn — the released self-influence implementation, evaluated on this use case directly.