Fabien Roger

Karma: 6,753

I am working on empirical AI safety.

Book a call with me if you want advice on a concrete empirical safety project.

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Evaluating honesty and lie detection techniques on a diverse suite of dishonest models

RowanWang, Sam Marks, Johannes Treutlein, evhub and Fabien Roger

25 Nov 2025 19:33 UTC

40 points

0 comments4 min readLW link

(alignment.anthropic.com)

Thinking about reasoning models made me less worried about scheming

Fabien Roger20 Nov 2025 18:20 UTC

79 points

7 comments12 min readLW link

Steering Language Models with Weight Arithmetic

Fabien Roger and constanzafierro

11 Nov 2025 16:30 UTC

81 points

2 comments5 min readLW link

Rogue internal deployments via external APIs

Fabien Roger and Buck

15 Oct 2025 19:34 UTC

34 points

4 comments6 min readLW link

Current Language Models Struggle to Reason in Ciphered Language

Fabien Roger and Shiyuan Guo

14 Oct 2025 9:08 UTC

77 points

6 comments5 min readLW link

Training Qwen-1.5B with a CoT legibility penalty

Fabien Roger9 Oct 2025 21:33 UTC

68 points

7 comments4 min readLW link

Training fails to elicit subtle reasoning in current language models

mishajw, Fabien Roger, Hoagy, gasteigerjo, Joe Benton and Vlad Mikulik

9 Oct 2025 19:04 UTC

49 points

3 comments4 min readLW link

(alignment.anthropic.com)

Inoculation prompting: Instructing models to misbehave at train-time can improve run-time behavior

Sam Marks, Nevan Wichers, Daniel Tan, Aram Ebtekar, Jozdien, David Africa, Alex Mallen and Fabien Roger

8 Oct 2025 22:02 UTC

156 points

37 comments2 min readLW link

Four places where you can put LLM monitoring

Fabien Roger and Buck

9 Aug 2025 23:10 UTC

49 points

0 comments7 min readLW link

Why Do Some Language Models Fake Alignment While Others Don’t?

abhayesian, John Hughes, Alex Mallen, Jozdien, janus and Fabien Roger

8 Jul 2025 21:49 UTC

158 points

14 comments5 min readLW link

(arxiv.org)

What can be learned from scary demos? A snitching case study

Fabien Roger24 Jun 2025 8:40 UTC

22 points

1 comment7 min readLW link

Modifying LLM Beliefs with Synthetic Document Finetuning

RowanWang, Johannes Treutlein, Avery, Ethan Perez, Fabien Roger and Sam Marks

24 Apr 2025 21:15 UTC

70 points

12 comments2 min readLW link

(alignment.anthropic.com)

Reasoning models don’t always say what they think

Joe Benton, Ethan Perez, Vlad Mikulik and Fabien Roger

9 Apr 2025 19:48 UTC

28 points

4 comments1 min readLW link

(www.anthropic.com)

Alignment Faking Revisited: Improved Classifiers and Open Source Extensions

John Hughes, abhayesian, Akbir Khan and Fabien Roger

8 Apr 2025 17:32 UTC

146 points

20 comments12 min readLW link

Automated Researchers Can Subtly Sandbag

gasteigerjo, Akbir Khan, Sam Bowman, Vlad Mikulik, Ethan Perez and Fabien Roger

26 Mar 2025 19:13 UTC

44 points

0 comments4 min readLW link

(alignment.anthropic.com)

Auditing language models for hidden objectives

Sam Marks, Johannes Treutlein, dmz, Sam Bowman, Hoagy, Carson Denison, Kei Nishimura-Gasparian, 7vik, Akbir Khan, Austin Meek, Euan Ong, Christopher Olah, Fabien Roger, jeanne_, Meg, Drake Thomas, Adam Jermyn, Monte M and evhub

13 Mar 2025 19:18 UTC

142 points

15 comments13 min readLW link

Do reasoning models use their scratchpad like we do? Evidence from distilling paraphrases

Fabien Roger11 Mar 2025 11:52 UTC

127 points

23 comments11 min readLW link

(alignment.anthropic.com)

Fuzzing LLMs sometimes makes them reveal their secrets

Fabien Roger26 Feb 2025 16:48 UTC

65 points

13 comments9 min readLW link

How to replicate and extend our alignment faking demo

Fabien Roger19 Dec 2024 21:44 UTC

114 points

5 comments2 min readLW link

(alignment.anthropic.com)

Alignment Faking in Large Language Models

ryan_greenblatt, evhub, Carson Denison, Benjamin Wright, Fabien Roger, Monte M, Sam Marks, Johannes Treutlein, Sam Bowman and Buck

18 Dec 2024 17:19 UTC

490 points

75 comments10 min readLW link