Interactive tabletop systems are becoming popular platforms for group activities. However, current common tabletops do not provide capabilities to differentiate interactions among simultaneous users, i.e. to associate a touch point with its proper owner. My thesis proposes and explores the use of an important biometric property of users as the basis for touch discrimination on multi-user tabletops: Finger Orientation (FO). In this thesis, I first collect the FO ranges of users standing in different positions around a tabletop. Second, I implement a system that uses FO to determine where the users are standing, and based on that extrapolate the owner of the touch. Next, I evaluate the system with two separate experiments, present the results, and discuss all findings. Furthermore, I explore some enhancements with a simple quantitative study. My results indicate that finger orientation is a good natural biometric trait enhances multi-user recognition on tabletops.

Interactive tabletop systems are becoming popular platforms for group activities. However, current common tabletops do not provide capabilities to differentiate interactions among simultaneous users, i.e. to associate a touch point with its proper owner. My thesis proposes and explores the use of an important biometric property of users as the basis for touch discrimination on multi-user tabletops: Finger Orientation (FO). In this thesis, I first collect the FO ranges of users standing in different positions around a tabletop. Second, I implement a system that uses FO to determine where the users are standing, and based on that extrapolate the owner of the touch. Next, I evaluate the system with two separate experiments, present the results, and discuss all findings. Furthermore, I explore some enhancements with a simple quantitative study. My results indicate that finger orientation is a good natural biometric trait enhances multi-user recognition on tabletops.