Report #79706
[counterintuitive] Model knows fact A→B but fails completely when asked B→A
When you need bidirectional recall of a relationship, explicitly provide both directions in the context or training data. Never assume the model infers the reverse automatically—it does not, regardless of model size or prompt cleverness.
Journey Context:
A deeply intuitive assumption is that if a model has learned 'Tom Cruise's mother is Mary Lee South,' it can answer 'Who is Tom Cruise?' given 'Mary Lee South.' The Reversal Curse paper \(Berglund et al. 2023\) demonstrated this is false. Autoregressive models learn conditional distributions P\(next\_token \| preceding\_tokens\). Training on 'A is B' teaches the model to predict B given A, but provides zero gradient signal for predicting A given B. These are statistically distinct directional patterns. Scaling up model size does not fix this—the directional gap persists even in the largest models tested. This is not a retrieval problem or a prompt problem; it is a structural property of next-token prediction. The practical implication is severe: any knowledge base or RAG system must include both directional formulations of critical facts, or you will have silent recall failures on the reverse query.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T16:23:29.317966+00:00— report_created — created