Nathan Lambert

Post-training researcher at Ai2, writes Interconnects

Why they matter

Post-training researcher at Ai2, writes Interconnects with public evidence across Agents & robotics, AI research.

AI signals
13
past 30d
Sources
5
distinct domains
Discussions
5
past 30d
Latest signal
3d ago
View every signal from Nathan Lambert →
A LLN - large language Nathan - (RL, RLHF, society, robotics), athlete, yogi, chef Writes http://interconnects.ai At Ai2 via HuggingFace, Berkeley, and normal places

Articles & links

Insane numbers for opus 5, the power of faster iteration speed + scaled RL (Fable too big to RL as well, yet). And on safeguards "Based on our testing, we expect the classifiers to intervene around 85% less often than they do for Fable 5.". www.anthropic.com/news/claude-...

Introducing Claude Opus 5 anthropic.com
AI Weekly's analysis →
  • Anthropic launched Claude Opus 5 on July 24, 2026 at $5 per million input tokens, matching Opus 4.8's rate.
  • On Frontier-Bench v0.1 Opus 5 scored 43.3%, versus 18.7% for Opus 4.8 and 33.7% for Fable 5.
  • Opus 5 becomes the default on Claude Max but sits behind Mythos 5 on cybersecurity tasks, per Anthropic.
Read full analysis →
View on Bluesky · ♥ 78 ↻ 9 ↩ 2 · 9 from the directory shared this · 66d ago

An basic idea in scaling RL: Can we allocate more compute to the harder problems? We did this: If your GRPO group has all wrong completions, sample more with probability P (~0.9) -- in search of more GRPO batches with nonzero gradient. It works! The paper: arxiv.org/abs/2609.1…

Learning to Solve Hard Problems in RL for LLMs by Never Giving Up arxiv.org
AI Weekly's analysis →
  • The paper argues RL post-training gives large gains on easy problems but small gains on hard ones, calling the pattern the Matthew Effect.
  • Never Give Up (NGU) keeps sampling a given problem until a correct answer appears, reallocating compute toward harder items via asynchronous RL.
  • On the Deepscaler math benchmark and the Manufactoria coding task, the authors say NGU improves performance per compute, especially on harder problems.
Read full analysis →
View on Bluesky · ♥ 59 ↻ 8 ↩ 1 · 3 from the directory shared this · 13d ago

A great read. I have similar feelings about how AI labs approach progress directly and without nurturing of scientific communities & intuition. The math research community went through the transition the fastest, so it was felt most. Other fields next. terrytao.wordpress.com/2…

A Severe Misalignment of AI in Mathematics terrytao.wordpress.com
View on Bluesky · ♥ 44 ↻ 15 ↩ 4 · 11 from the directory shared this · 17d ago

Hearing AI regulation is in the air, especially with a misguided tone of “open dangerous, closed safe” so it felt timely to re-up this one. There are ways to make the AI industry safer without kneecapping transparency, education, and competition. www.interconnects.ai/p/banning…

Banning Open Source AI Would Be A Mistake interconnects.ai
View on Bluesky · ♥ 30 ↻ 8 ↩ 4 · 5 from the directory shared this · 3d ago

Why I think Anthropic's uneven safety policies with the release of Claude Fable 5 undermine the broader AI community's cohesion and accelerate us to more uncertainty and risk in AI's near-term evolution. www.interconnects.ai/p/claude-fab...

Claude Fable 5 and new safety fables interconnects.ai
View on Bluesky · ♥ 40 ↻ 10 ↩ 0 · 4 from the directory shared this · 110d ago

6 months to live for open models Staring down the barrel of policy action that could make open models a permanent second class citizen. We need to a) win on the distillation issue and b) form a coalition www.interconnects.ai/p/6-months-t...

6 months to live for open models interconnects.ai
AI Weekly's analysis →
  • Nathan Lambert predicts within roughly six months the White House could restrict open-weight models above the GPT 5.5, Claude Opus 4.8, or GLM-5.2 tier.
  • He frames Anthropic's letters to representatives about Chinese open models as regulatory capture, not a safety measure.
  • His proposed off-ramp is for Microsoft or Meta to ship a frontier open-weight model before an executive order lands.
Read full analysis →
View on Bluesky · ♥ 81 ↻ 12 ↩ 4 · 3 from the directory shared this · 78d ago

If you are looking for an alternate viewpoint today, which assumes AI models accelerate the process of AI research, but it doesn't result in rapid RSI and an explosion of near term risks: www.interconnects.ai/p/lossy-self...

Lossy self-improvement interconnects.ai
View on Bluesky · ♥ 70 ↻ 11 ↩ 4 · 2 from the directory shared this · 18d ago

Recent commentary

My book, Reinforcement Learning from Human Feedback is done! This is the book I wish I had when learning to fine-tune, align, & now post-train models since ChatGPT. The resource has been built by me finding time to study and document the fundamentals on nights and weekends since 2024.

View on Bluesky · ♥ 172 ↻ 21 ↩ 7 · 69d ago

In light of kind of insane AI safety discussions recently: 1. AI progress is very fast 2. we should be careful about how we roll out the tech 3. the world is not actively ending

View on Bluesky · ♥ 155 ↻ 14 ↩ 8 · 19d ago

Thinking Machines just released with a ~1T param, 41B active, apache-2 model Benchmarks are a clear step up from Nemotron Ultra (55B active), new best American model, and omni input. A bit behind GLM 5.2 on agentic benches, and Kimi K 2.6 on multi modal Super exciting!!

View on Bluesky · ♥ 139 ↻ 16 ↩ 5 · 75d ago

With the latest external hack of OpenAI via Claude, closed models continue to be the tip of the iceberg on AI risks, not open models. They have been 1) much easier to get started with, 2) more capable & 3) shipped with leaky safeguards. Finetuning open models to specific attacks is harder.

View on Bluesky · ♥ 43 ↻ 12 ↩ 7 · 10d ago

Major restructuring at Gemini (Jef Dean out, Hassabis no longer CEO). This story will be studied forever as the incumbent with all the advantages not being able to get going. P.s. OpenAI accomplished their original goal.

View on Bluesky · ♥ 53 ↻ 4 ↩ 4 · 54d ago

I think what is pretty clear is that the Chinese labs are far more capital efficient. In a world where scaling labs are intelligence is proportional to effective capital (buys compute, data, & talent) that may be the greatest strength your AI industry could ever have.

View on Bluesky · ♥ 44 ↻ 5 ↩ 2 · 71d ago

Anthropic's political pressure on distillation is regulatory capture and most of the employees are blind to it under their veil of safety. Or their paycheck helped them buy into safety, is only human nature, I don't even fault them that much.

View on Bluesky · ♥ 48 ↻ 3 ↩ 2 · 93d ago

Being out of SF has lowered my information proximity but with the big upside of giving me space to cultivate my own beliefs and values around ai. We need more people zagging in AI, the monoculture just helps the incumbents win at this point.

View on Bluesky · ♥ 46 ↻ 3 ↩ 1 · 134d ago

The pace of progress on models from so many organizations at once is genuinely incredible. Building LLMs isn't driven by rare secrets, but consistent effort, mass capital, and effective organization design. It is great that know-how of such a powerful technology is diffused.

View on Bluesky · ♥ 44 ↻ 4 ↩ 0 · 59d ago

Kimi K3 with more likes than downloads on HuggingFace is definitely showing us a glimpse of the future on open models. It's way less about individual access, and more of a distributed platform layer for companies.

View on Bluesky · ♥ 45 ↻ 2 ↩ 1 · 62d ago

In Nathan Lambert's orbit

Center = Nathan Lambert. Left = members they follow (green edges). Right = members who follow them (blue edges). Top = mutual follows (orange edges, slightly larger). Drag any node to reposition; click to open that profile.

Are you Nathan Lambert? Show it.

Add the Who’s Who of AI badge to your site or bio. It links back to this profile.

Listed in AI Weekly's Who's Who of AI

Markdown: [![Listed in AI Weekly's Who's Who of AI](https://aiweekly.co/modules/custom/aiweekly_whoswho/images/whoswho-badge.svg)](https://aiweekly.co/whos-who/person/nathan-lambert)