InterpretabilityResearch

Privileged Bases in the Transformer Residual Stream

Mar 16, 2023
Read Paper

Abstract

Our mathematical theories of the Transformer architecture suggest that individual coordinates in the residual stream should have no special significance (that is, the basis directions should be in some sense "arbitrary" and no more likely to encode information than random directions). Recent work has shown that this observation is false in practice. We investigate this phenomenon and provisionally conclude that the per-dimension normalizers in the Adam optimizer are to blame for the effect.

We explore two other obvious sources of basis dependency in a Transformer: Layer normalization, and finite-precision floating-point calculations. We confidently rule these out as being the source of the observed basis-alignment.

Related content

Discovering cryptographic weaknesses with Claude

cryptographic algorithms. The first attack significantly weakens HAWK, a digital signature scheme that was built for a future world where quantum computers are able to break existing standards. The second identifies a new way to attack round-reduced AES, the most widely used symmetric cipher.

Read more

Project Pilot: Can AI control a drone?

Working with Andon Labs, we’ve developed a new series of evaluations that assess AI models’ ability to use a flying drone, culminating in a new benchmark: Drone-Bench.

Read more

How Canada uses Claude: Findings from the Anthropic Economic Index

Read more