This book constitutes the refereed proceedings of the Second International Conference on Formal Concept Analysis, ICFCA 2004, held in Sydney, Australia in February 2004.The 27 revised full papers presented together with 7 invited papers were carefully reviewed and selected for inclusion in the book. Formal concept analysis emerged out of efforts to restructure lattice theory and has been extended into attribute exploration, Boolean judgment, and contextual logics in order to create a powerful general framework for knowledge representation and formal reasoning; among the application areas of formal concept analysis are data and knowledge processing, data visualization, information retrieval, machine learning, data analysis, and knowledge management. The papers in this book address all current issues in formal concept analysis, ranging from foundational and methodological issues to applications in various fields.