This book constitutes the refereed proceedings of the IFIP TC13 International Conference on Human-Computer Interaction, INTERACT 2005, held in Rome, Italy in September 2005. The 70 revised full papers and 53 revised short papers presented were carefully reviewed and selected from 264 submissions. The papers are organized in topical sections on haptic and tangible interfaces, novel user interfaces, search techniques, model-based design, interacting with mobile devices, accessibility, intelligent interfaces, large displays, collaboration, usability evaluation, children’s interfaces, PDA usability, social interaction, multimodal interfaces, context of use, 3D and virtual environments, CSCW, understanding users, interface design, eye-tracking, video browsing, user studies, visualization techniques, location awareness, context awareness, group work, computer-mediated communication, adaptive and adaptable systems, universal access, and tools.