A user's interest in a web page can be estimated by unobtrusively (implicitly) observing his or her behaviour rather than asking for feedback directly (explicitly). Implicit methods are naturally less accurate than explicit methods, but they do not waste a user's time or effort. Implicit indicators of a user's interests can also be used to create models that change with a user's interests over time. Research has shown that a user's behavior is related to his/her interest in a web page. We evaluate previously studied implicit indicators and examine the time spent on a page in more detail. For example, we observe whether a user is really looking at the monitor when we measure the time spent on a web page. Our results indicate that the duration is related to a user's interest of a web page regardless a user's attention to the web page.
Kim, H., Chan, P.K. (2005). Implicit indicators for interesting web pages (CS-2005-05). Melbourne, FL. Florida Institute of Technology.