Activation Patching
An interpretability technique that proves a network component handles a specific concept by pasting its clean activations into a corrupted forward pass and w...
Think of It Like This
Like bypassing a broken house fuse with a battery to prove that specific fuse controls the kitchen lights.
This causal intervention is critical for mechanistic interpretability. Probing only shows correlation, but overwriting a live activation proves that the overwritten component was the causal source of the behavior. By sweeping this patch across layers, researchers can locate the exact circuits responsible for a specific concept.