Whetheryouareacomputerscientist, alogician, aphilosopher, orapsychologist, it is crucial to understand the role that context and contextual information plays in reasoning and representation. The conference at which the papers in this volume were presented was the fourth in an international series devoted to research on context, and was held in Stanford (USA) on June 23-25, 2003. The ?rst conference in the series was held in Rio de Janeiro (Brazil)...