Abstract Summary
The paper gives a brief overview of the four shared tasks organized in the PAN 2026 lab on digital text forensics and stylometry to be hosted at CLEF 2026. The goal of the PAN lab is to advance the state-of-the-art in text forensics and stylometry through an objective evaluation of new and established methods on new benchmark datasets. Our five tasks in 2026 will be: (1) Voight-Kampff Generative AI Detection, particularly in mixed and obfuscated authorship scenarios, (2) Text Watermarking, a new task that aims to find new and benchmark the robustness of existing text watermarking schemes, (3) Multi-author Writing Style Analysis, a continued task that aims to find positions of authorship change, (4) Generative Plagiarism Detection, a continued task that targets source retrieval and text alignment between generated text and source documents, (5) Reasoning Trajectory Detection, a new task that deals with the source detection and safety detection of LLM-generated or human-written reasoning trajectories. As in previous editions, PAN invites software submissions as easy-to-reproduce docker containers; more than 1,100 of softwares have been submitted since PAN~2012, with all recent evaluations running on the TIRA experimentation platform.
