Alex Meinke — LessWrong

Principles for Embedded Evaluations

by Axel Højmark, Alex Meinke, and Marius Hobbhahn

This is a linkpost for https://www.apolloresearch.ai/blog/principles-for-embedded-evaluations Blog post > In September 2026, leaders of frontier AI companies called for pacing the frontier of AI development, with embedded evaluators as the first step. Frontier AI companies committed to giving outside evaluators employee-like access to their training, evaluation, and deployment, and some...

Sep 3024

Measuring Reward-Seeking via Contrastive Belief Updates

by Jérémy Scheurer, Axel Højmark, jenny, Felix Hofstätter, Theodore Ehrenborg, Bronson Schoen, and Alex Meinke

This is a linkpost for https://rewardseeking.ai/ Machine learning models can produce the right outputs for the wrong reasons. Famous examples include a reinforcement learning agent that, rewarded for collecting a coin always placed at the right end of the level, learns to run rightward rather than to seek the coin...

Jul 2191

11 Open Empirical Problems in Reward-Seeking

We recently published our paper on "Measuring Reward-Seeking via Contrastive Belief Updates". We're excited about research like this, and there are many more open problems than we can work on. Here's a list of open problems that we think are valuable. If you work on/solve these problems, we'd be happy...

Jul 2166

We need 3rd party Training-Run Evaluations

Training-Run Evaluations conducted by a 3rd party should become a standard part of frontier AI safety. By a Training-Run Evaluation, or TRE, I mean an in-depth analysis of the post-training pipeline and dynamics leading up to a frontier model release. A TRE can look at intermediate checkpoints, training rollouts, RL...

Jul 5177

Physics of RL: Toy scaling laws for the emergence of reward-seeking

TL;DR: * When is or isn't reward the optimization target? I use a mathematical toy model to reason about when RL should select for reward-seeking reasoning as opposed to behaviors that achieve high reward without thinking about reward. * Hypothesis: More diverse RL increases the likelihood that reward-seeking emerges. *...

Mar 4121

Stress Testing Deliberative Alignment for Anti-Scheming Training

by Mikita Balesni, Bronson Schoen, Marius Hobbhahn, Axel Højmark, Alex Meinke, Teun van der Weij, Jérémy Scheurer, Felix Hofstätter, Nicholas Goldowsky-Dill, rusheb, Andrei Matveiakin, jenny, and alex.lloyd

Twitter | Microsite | Apollo Blog | OpenAI Blog | Arxiv Before we observe scheming, where models covertly pursue long-term misaligned goals, models might inconsistently engage in various covert behaviors such as lying, sabotage, or sandbagging. This can happen for goals we give to models or they infer from context,...

Sep 17, 2025134

Ablations for “Frontier Models are Capable of In-context Scheming”

We recently published our paper “Frontier Models are Capable of In-context Scheming”. We ran some follow-up experiments that we added to the paper in two new appendices B.5 and B.6. We summarize these follow-up experiments in this post. This post assumes familiarity with our paper’s results. sonnet-3.5 sandbags to preserve...

Dec 17, 2024116