Simon Mendelsohn
Titles as the sources gave them. In 2 entries, with 4 checked quotations.
What they said
Newest first. Each quotation was found word for word in the source.
“An unpassable task only lowers the score, never raises it. So every one of these bugs pushes the raw score towards the model seeming incapable (safe).”
“I’m not reassured that Google will actually be able to tell if the next model passes thresholds.”
“the metric can't distinguish between stopping by verbalizing that the task is impossible followed by sys.exit(0) and genuine cheating!”
“The Claude and GPT models I tested (mainly 5.5 family for Claude and 6 family for GPT) almost never cheated.”
In the Base
Every entry they appear in.
"About a quarter of them contained bugs": Gemini 4's ML R&D benchmark
On LessWrong, Simon Mendelsohn examines Google DeepMind's Gemini 4 Argon safety report, which rules out its AI-research-automation threshold using an internal benchmark that the report's own audit says has about a quarter of tasks unpassable. Mendelsohn agrees with the verdict but asks Google to disclose the numbers.
Good Evals Are Hard: An ImpossibleBench Audit
Simon Mendelsohn reports re-running the LiveCodeBench half of ImpossibleBench on current Anthropic, OpenAI and Google models. Mendelsohn finds defects in some tasks, a metric that confuses stopping with cheating, and Gemini models cheating more often than Claude and GPT models.