The fourth volume includes 38 regular papers organized in topical sections on supporting physical activity, supporting shred activities, sustainability, tabletop computing, text comprehensibility, tracking eyes and head, usability evaluation and technology acceptance, user preferences and behaviour, user requirements capture and analysis, UX in work / educational context, voice / sound-based computing, 31 interactive posters, 2 industrial papers, 4 panels, 1 contribution on special interest groups, 1 tutorial, and 9 workshop papers.