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Eric Bigelow

Things Eric Says on Podcasts

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Eric Bigelow has been a guest on The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis .

Recently: “How Agents Decide: Goodfire's Eric Bigelow on Critical Tokens, Phase Shifts, & In-Context Learning” on The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis (October 2026).

What They Said

“If you optimize for a chain of thought being monitorable, then sometimes the chains of thought are less faithful. And what you end up with is a different objective function that now is prioritizing, I'm going to learn intermediate steps that look sensible, whether or not they are sensible.” — Eric Bigelow, The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis

The host asked why models' written-out reasoning is drifting into a strange dialect of its own. Bigelow points to Goodhart's law: reward only the final answer and nothing keeps the steps human-readable, and rewarding readable steps can get you steps that merely look right. He says he was much more optimistic about monitoring chains of thought a year ago.

The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis · 2026-10-10 Permalink → Listen →
The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis Around 1:21:24 into the episode
Eric Bigelow

…to like trying to wrap my head around that and trying to think about like what's going on inside the latent chain of thought and how do we how do we think about that with some of the some of the tools that we have and even just metaphors that we as scientists use for understanding the models.

Speaker 2

…explanation, but they certainly have been saying, we're looking into this. It's important. We want to figure out why this is happening. Any intuitions that you would offer that people might want to take inspiration from, chase down, put into the hopper at OpenAI for what the hell is going on there?

Eric Bigelow

Yeah, I think that reasoning kind of presents this really interesting challenge of distribution shift where when we like RL in general, where when you're doing RL, whether it's with like a single model or with sub-agents, there isn't necessarily an incentive to keep things human readable, right? Like the objective is to find the, to have the final, if you're doing like outcome level verification instead of process level verification, then your objective is to basically have a better final answer by whatever means possible. And it kind of reminds me of like things with like language evolution with people where like if you look at a long enough time scale, like human languages change. There isn't really like any driving force that forces the English language to stay exactly as it is today as it was 300 years ago or 600 years ago. And languages do change. I mean, there's like exceptions to this. Like the French government, as I understand, has an institution for sort of keeping the language as it is and has had that for a very long time, which has sort of resisted forces of…

Nathan Labenz

So if

Speaker 2

I'm trying to square your comments just now about this quick dramatic evolution of language within chain of thought and within agent agent. Your earlier thoughts on why continual learning won't make things like totally impossible to interpret. Is it just a question of scale? Is it like your model…

Eric Bigelow

just to be clear, when you talk about continual learning, you're talking about the world where we're actually fine-tuning models for each person, right? Actually, like changing their weights. Is that right?

Speaker names from our own diarization · position estimated from where the line sits in the episode
“If you look at DeepSeek R1's outputs, they'll say "wait" 50 times or more in a single reasoning chain. That's a lot of epiphanies to have when you're working through one problem.” — Eric Bigelow, The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis

Bigelow, an interpretability researcher at Goodfire, was asked how models have changed over the last two years. His answer is that reasoning models get around their inability to backtrack by listing every possibility they can think of and choosing among them afterwards, which is why he calls "reasoning" close to a misnomer for what they do.

The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis · 2026-10-10 Permalink → Listen →
The Cognitive Revolution" | AI Builders, Researchers, and Live Player Analysis Around 35:54 into the episode
Eric Bigelow

…best guess is that we're going to see more context engineering and more of this kind of thing, more harnesses, more memories. And I think that's really what we've seen in the last year or so with the rise of agents is a lot of that engineering is just going into putting a lot of stuff in context.

Speaker 2

…researchers based on just how dialed in they seem to be? And I'm also just interested, do you even know like how sampling is being done these days? It's a very in the weeds question. But yeah, tell me the story of the last two years. How do you understand how models have changed during that time?

Eric Bigelow

I'll say first that I wish I knew what the sampling parameters were for the Claude API and for the latest GPT models. I think it's very unfortunate that they've talked these away. I expect that it's probably similar things happening. It's just that they want to limit how much people can reverse engineer the models and play with temperature to do a lot of systematic. Like I think a lot of the people that are doing really systematic prompting are using like a lot of hitting the cloud API with millions and millions and billions even of token requests. There's a high risk that they're doing something, you know, a little bit nefarious or trying to distill models or extract model weights in some way or another. So I think that's probably the main reason why they did this rather than that they're actually doing a different sampling scheme under the surface. Although I would love to learn more and I'd be happy to be surprised. As for the story for the last couple of…

Speaker 2

When you do research, how do you choose what model to work with? Obviously, a lot of people are choosing based on what the compute resources they have available support. And I'm sure that's a factor for you too. But at Goodfire, you guys have significant resources and you've built some…

Eric Bigelow

So I think I think of them as in large part standing in for each other. There are idiosyncrasies of like Quen really likes to think in Chinese. And if you do the logit lens on Quen, sometimes there will be a lot of Chinese characters sort of in the middle before it starts out putting English tokens…

Speaker 2

does that mean that interpretability research today outside of proprietary model companies is becoming dependent on chinese models is there an american model that you could use as a substitute for chime k3 that you feel like wouldn't lose that much of the value or are we like we have to use chinese…

Speaker names from our own diarization · position estimated from where the line sits in the episode

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