Reasoning-Prefill Test Suggests Qwen 3.8 Was Trained on GPT-5.5 Pro Traces, Answer Overlap Jumps 18 Points
Summary
An independent experiment posted September 9 shows that prefilling the first 1% of GPT-5.5 Pro's reasoning trace into Qwen 3.8 A95B raises its answer overlap with GPT-5.5 Pro from 16.79% to 34.97%, a +18.18 pp jump concentrated on STEM problems (+26.99 pp). The author frames the effect as evidence that Qwen may have been trained on GPT-5.5 Pro or a closely related model, contrasting with an earlier run where prefilling Claude Opus traces produced almost no shift. The gist trended on Hacker News with 117 points and 55 comments.
Originally reported by gist.github.com
Read the original article →Original headline: Reasoning-Prefill Test Suggests Qwen 3.8 Was Trained on GPT-5.5 Pro Traces, Answer Overlap Jumps 18 Points