I'm very worried about changes to AI architectures that result in AIs thinking in opaque activations instead of in chain of thought (aka "neuralese" architectures). Based on limited public evidence, it seems like Astra was a concerning step in this direction. Unfortunately, there was insufficient public information to have a well-informed public scientific discussion about whether the changes to architectures and training methods that went into Astra were a good trade-off between monitorability and performance. We also don't know how AI companies will make these trade-offs going forward. I think companies should release the evidence needed for a reasonably informed public conversation about how these trade-offs should be made. They should also make and publish their policies around this. We've written up a proposal for how this could work. I don't know if this proposal will be sufficient to avoid the most concerning architectures, but it seems like a relatively robust step in the right direction. AI companies should be very cautious about pursuing architectures that could eliminate or greatly reduce dependence on chain of thought, and certainly shouldn't do this before the rest of the world has a chance to discuss the evidence and their policies.