This report documents research undertaken in the summer of 2001 to investigate the nature of visitor experiences at the Explore@Bristol interactive science museum. The experimental work involved an observational study of visitor behaviour at six of the exhibits in Explore, augmented by interviews and discussions. The outcome is a provisional model of visitor experience identifying three dimensions that might make such experiences compelling: Drama /Sensation, Challenge/Self Expression, and Social. Though developed in the context of Explore, we consider the model to have wider application in the consumer space. Notes: Enquiries concerning this report should be directed to Richard Hull email: rh@hplb.hpl.hp.com