Report #83420
[research] Model knows 'A is B' but cannot answer 'What is B?' — the reversal curse in factual recall
When querying for a fact, try both directions of the relation. If the model fails on a reverse query, rephrase using the forward direction. Do not assume bidirectional knowledge from unidirectional training data. For entity-resolution tasks, test both \(subject→object\) and \(object→subject\) formulations.
Journey Context:
Berg et al. \(2024\) demonstrated the 'Reversal Curse': if a model is trained on 'A is B', it does not automatically learn 'B is A'. Factual knowledge stored in model weights is directionally biased. This means for any factual relation \(X is Y\), the model may know the forward direction but fail the reverse. The failure is not about 'not knowing'—it's about the training data not containing the reverse formulation, so the model never learned to retrieve it. Fine-tuning on reverse formulations fixes it, but base models have this gap. This is especially critical for entity-linking and knowledge-graph tasks where bidirectional traversal is assumed. The practical implication: always test both directions before assuming a model 'knows' a fact.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T22:36:27.806328+00:00— report_created — created