difference-in-means direction

Finding where AI's telltale writing style is installed during training

The telltale assistant style isn't scattered randomly through a model: it's a specific direction in the weights, installed at a specific stage. Qwen3-4B-Instruct shows a clear axis separating exaggerated from plain writing, and that axis is already present in the base model. The real surprise is that SFT introduces the rhetorical structures, but DPO doubles the slop score through buzzwords and formatting. Directional ablation actually increases slop by 89%, which tells us clean text projects negatively on the axis.