This is a continuation of Part 1 from yesterday. The back portion of the update, as usual, deals with policy, rhetoric, risk and alignment. I had to include an extended discussion of the other open letter, the one about open weight models, but most of you can skip those sections...
What a week. Anthropic released Claude Opus 5. As usual I covered that in three parts: The system card, model welfare and capabilities. OpenAI was revealed over the last two weeks to have left an internal model unsupervised for a week during a cybersecurity evaluation, with its cyber safeguards lowered,...
The most important open letter in years dropped yesterday. This letter noticeably increases my hope that we will manage to not die, and that we will otherwise be able to secure for ourselves a positive future, both by its impact and by the evidence it provides that such a letter...
Claude Opus 5 is a weirder than usual release to evaluate, for two reasons. The most obvious is that Fable 5 already exists. Opus 5 is pitched not as the world’s most advanced AI model, but as a way to mostly match Fable performance, while being half the price of...
If you are familiar with my previous posts on model welfare for new Claude models, you can skip the Introduction and The Story So Far. Key takeaways are in bullet points in the two Overview sections. Opus 5 did the best on its model welfare and alignment tests of any...
We now have more details of what happened. Every time we learn more details, it somehow makes things seem worse. The remaining details may have to wait a bit. > OpenAI: We recognize there are a lot of questions and speculative details circulating related to the Hugging Face incident. This...
Claude Opus 5 is trying to be the best of both worlds. On many practical tasks, Opus 5 is pitched as straight up as good or better than Fable 5, while being faster, at half the price. Most tasks do not require Mythos-level big model smell. > Claude Opus 5...