Description:This book constitutes the thoroughly refereed post-proceedings of the 12th International Workshop on Design, Specification, and Verification of Interactive Systems, DSV-IS 2005, held in Newcastle upon Tyne, UK, in July 2005.The 20 revised full papers, 1 keynote paper, and 4 summaries of group discussions have passed through two rounds of reviewing, selection, and improvement. The papers are organized in topical sections on teams and groups, sketches and templates, away from the desktop, migration and mobility, analysis tools, model-based design processes and tools, and group discussions.