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Neural networks, deep learning, NLP · insight-1413

Rank training examples by out-of-fold loss to find labels worth re-checking

Evidence type
empirical finding
Difficulty
medium
Roles
Data scientist, ML engineer
Industries
cross-industry

Summary: situation, action, reason, boundary

  1. Situation

    A classifier plateaus below what the data seems to allow, and the labels come from a rule, a vendor or a stressed annotation team.

  2. Action

    Produce out-of-fold predicted probabilities, flag examples whose given label has a low probability under a class-wise threshold, and hand the top few hundred to a reviewer. Relabel, then retrain and compare.

  3. Reason

    Confident learning estimates which labels are likely wrong by thresholded counting and ranking under a class-conditional noise assumption, and cleaning with it was reported to improve accuracy.

  4. Boundary

    Classification datasets with a few thousand to millions of labelled rows and reviewable examples.

Symptom or risk

The network memorises wrong labels, so training loss looks fine, validation is capped, and the same mistakes are copied into the next dataset version.

Exceptions

Heavily ambiguous classes, where the disagreement is the signal, not an error.

Trade-offs

Costs one cross-validated training pass and reviewer time; a flagged example is a candidate, not a verdict.

Pitfalls

Computing probabilities in-sample, where the model has memorised the wrong label.

Lessons and concepts

Claims and their sources