We’ll be able to fine-tune in the test environment so won’t experience OOD at deployment, and while changes will happen, continual fine-tuning will be good enough to stop the model from ever being truly OOD. We think this may apply in settings where we’re using the model for prediction, but it’s unclear whether continual fine-tuning will be able to help models learn and adapt to the rapid OOD shifts that could occur when the models are transferred from offline learning to online interaction at deployment.
Couldn’t the model just fail at the start of fine-tuning (because it’s causally confused), then learn in a decision setting to avoid causal confusion, and then no longer be causally confused?
If no—I’m guessing you expect that the model only unlearns some of its causal confusion. And there’s always enough left so that after the next distribution shift the model again performs poorly. If so, I’d be curious why you believe that the model won’t unlearn all or most of its causal confusion.
Here we’re saying that the continual fine-tuning might not necessarily resolve causal confusion within the model; instead, it will help the model learn the (new) spurious correlations so that it still performs well on the test data. This is assuming that continual fine-tuning is using a similar ERM-based method (e.g. the same pretraining objective but on the new data distribution). In hindsight, we probably should have written “continual training” rather than specifically “continual fine-tuning”. If you could continually train online in the deployment environment then that would be better, and whether it’s enough is very related to whether online training is enough, which is one of the key open questions we mention.
Couldn’t the model just fail at the start of fine-tuning (because it’s causally confused), then learn in a decision setting to avoid causal confusion, and then no longer be causally confused?
If no—I’m guessing you expect that the model only unlearns some of its causal confusion. And there’s always enough left so that after the next distribution shift the model again performs poorly. If so, I’d be curious why you believe that the model won’t unlearn all or most of its causal confusion.
Here we’re saying that the continual fine-tuning might not necessarily resolve causal confusion within the model; instead, it will help the model learn the (new) spurious correlations so that it still performs well on the test data. This is assuming that continual fine-tuning is using a similar ERM-based method (e.g. the same pretraining objective but on the new data distribution). In hindsight, we probably should have written “continual training” rather than specifically “continual fine-tuning”. If you could continually train online in the deployment environment then that would be better, and whether it’s enough is very related to whether online training is enough, which is one of the key open questions we mention.