Continual fine-tuning and catastrophic forgetting
Continual fine-tuning involves adapting a model to new tasks while retaining performance on previous tasks. However, this can lead to catastrophic forgetting. Catastrophic forgetting in LLMs refers to the phenomenon where a model loses previously learned information when fine-tuned on new tasks or data without appropriate mechanisms to preserve prior knowledge.
Let’s implement a simple strategy to mitigate this:
- First, we calculate parameter importance and implement elastic weight consolidation (EWC) loss for preserving critical weights:
import copy def ewc_loss(model, old_model, importance, loss): ewc_lambda = 0.01 for n, p in model.named_parameters(): if n in importance: loss += ewc_lambda * importance[n] &...