In this thesis we explore a different kind of computer-mediated collaboration (CMC) in which two people collaborate to perform a single task in a time-sensitive asymmetric situation wherein one person is more invested in the outcome than the other is. Our conjecture is that interactive computing can quickly communicate intent, which may help mediate time-sensitive asymmetric tasks between two people. We explore this idea specifically in the context of asking a stranger to take one's picture at a tourist site. Consider a tourist handing a cell phone to a complete stranger and asking the stranger to take the tourist's picture in front of a landmark. This collaboration often leaves the tourist unhappy with the final image. The tourist cannot quickly communicate the intended framing to the stranger who is, quite likely, in a hurry and, frankly, not interested in the final picture's quality. We explore mediation of this interaction with a mobile app, titled extit{Cake Cam}. Cake Cam is a computing tool used to communicate intent in time-sensitive asymmetric tasks wherein one collaborator is more interested in the outcome's quality than the other. To use the app, a tourist takes a photo of the scene, carefully framed to his or her desires. The tourist then hands the phone to a stranger, asks the stranger to take the tourist's picture, and moves into the frame. Augmented reality alignment markers guide the stranger into taking the photo the tourist initially framed, producing the intended photo. We found that Cake Cam was more effective and efficient in guiding users into replicating a photo than verbal descriptions were. On average it took almost 3 more tries for the participant to take the correct photo without Cake Cam, than with it. Additionally, with Cake Cam, the final photo was closer to the intended framing by an average 9 cm. Participants that used Cake Cam found the process to be less difficult and were more confident they had captured the intended photo than the participants that used the normal camera app.



College and Department

Physical and Mathematical Sciences; Computer Science



Date Submitted


Document Type





Human Computer Interaction, Computer Mediate Collaboration, Collaborative Photography, Real-Time Aesthetic Guidance