An increasing amount of cancer patients visit the Internet for information and use online communities. However, robust evidence on what patients seek and how these online activities affect patient-provider communication during consultations is lacking. In my four-year PhD project I will use a combination of innovative methods (i.e., combining automatic content analysis and supervised machine learning with survey research) in order to create insights in what content is used by patients, how online interaction occurs as well as how seeking behaviour can be explained. Next, a role-played consultation with patients will put these insights into the setting of the medical consultation. This way, the beneficial or detrimental effects of using online health information prior to consultation on patient outcomes can be studied.