The key insight is that knowledge editing isn't just about writing new information—deciding when NOT to apply edits is equally important. A routing mechanism that separates edit injection from suppression outperforms simply adding more model capacity.
This paper tackles knowledge editing—updating specific facts in language models while keeping other knowledge intact. It proposes a dual-adapter system with a router that decides when to apply edits: some prompts get an edit adapter (to learn new facts), while others get a locality adapter (to preserve original knowledge).