This is the presentation of my Ph.D. defense in February 2015.
The aim of my thesis is to provide a deeper understanding of how users engage with websites and how to measure this engagement. We start with studying online behaviour metrics, which are commonly employed as a proxy for user engagement, and we propose new metrics that expose so far unconsidered aspects of user engagement. We then conduct several case studies that demonstrate how these metrics provide a deeper understanding of user engagement. Within each case study we also examine how the characteristics of a website influence user engagement.