Welcome to the 4th IEEE InternationalWorkshopon Human – Computer Int- action, HCI 2007. Human – computer interaction (HCI) is one of the foremost challengesofoursociety.Newparadigmsforinteractingwithcomputersarebeing developedthatwill de?ne the 21stcenturyandenable the worldtocommunicate and interact e?ortlessly and intuitively. The goal of this workshop is to bring together researchers whose work is related to human – computer interaction, share novel ideas, and stimulate new research directions. This year we received 113 submissions from more than 18 countries. Based upon the double-blind reviews of the program committee, 15 papers were accepted for oral presentation and publication in the proceedings. We would like to thank all of the members of the ProgramCommittee. Their reviews of the submissions as always played a pivotal role in the quality of the workshop.Furthermore,wewouldliketoacknowledgeoursponsorsandsuppo- ers, the Leiden Institute of Advanced Computer Science at Leiden University, the Faculty of Science at the University of Amsterdam, the Beckman Institute atthe UniversityofIllinoisatUrbana-Champaign,BSIK/BRICKS/FOCUS,the Netherlands National Science Foundation (NWO) and IEEE. Finally,specialthanksgotoBartThomee,whometthemyriadandunexpected challengesoforganizingthis workshopwith generousandtirelessdedication.