The aim of IFIP Working Group 2.7 (13.4) for User Interface Engineering is to investigate the nature, concepts and construction of user interfaces for software systems. The group's scope is: - developing user interfaces based on knowledge of system and user behaviour; - developing frameworks for reasoning about interactive systems; and - developing engineering models for user interfaces. Every three years, the group holds a "working conference" on these issues. The conference mixes elements of a regular conference and a workshop. As in a regular conference, the papers describe relatively...