The addiction associated with MMORPGs is rising. This dissertation from the University of Salford, looks into the reasons why addiction occurs and compares them to the reasons people play online games, with the goal of highlighting the key motivational factors linked to the formation of addictive behaviors.
In this MFA thesis from Rhode Island School of Design, Andrew Y. Ames develops a theory of interactivity from Noah Wardrip-Fruin's concept of playable media, Domini Lopes' strongly interactive art, Eric Zimmerman's defined modes of interactivity, and Ian Bogost's procedural rhetoric.
Christopher W. Totten's master's thesis is about the things real-world architecture can learn from game design. In this article, which also contains a PDF download of his paper, he explains how he contacted members of Valve and got their help researching the things that planners of real spaces can learn from those who design virtual ones.