He holds a PhD with honors from Eindhoven University of Technology and has expertise in user experience and longitudinal studies in HCI, most recently with a focus on behavior change support systems. His book on "Modeling users' experiences with interactive technologies" was published by Springer in 2012. His work has been published among others at CHI, TOCHI and IJHCS. He has been a visiting researcher at Philips Research, Philips Consumer Lifestyle and the HCI Institute at Carnegie Mellon University.