93.2% macro-F1 for human vs. AI detection and 68.4% macro-F1 for six-way authorship attribution
This isn't what I'd call "reliable".
I'm also not impressed with their methodology, which is heavily based on Gemini.
To generate mirrored AI stories, we reverse-engineer writing prompts from each human story by prompting Gemini 2.5 Flash (Gemini Team, 2025a) to infer the underlying premise
That's too many steps removed from anything you'd encounter in the wild. They're not even testing against human-prompted output.
And then they use Gemini again to analyze all the stories. Relying on proprietary cloud models for the core of your analysis is like building on sand.
