This special issue of Erkenntnis collects a selection of papers from participants of the 9th Formal Epistemology Workshop (FEW), held at the Munich Center for Mathematical Philosophy, May 29–June 1, 2012. We would like to express our gratitude to all the people who contributed in making the workshop a great event on all accounts: Hannes Leitgeb, all speakers, discussants, and attendees, Roland Pöllinger and the MCMP staff.