Improving Menu Placement Strategies for Pen Input

Pen-based interaction is becoming a commonplace two degree-of-freedom alternative to the mouse. The use of pen input allows users to acquire targets directly on a computer display. This style of interaction introduces a unique form factor and a new set of considerations in the design of applications for such devices. This thesis presents a series of experiments designed to evaluate the use of pen-input devices on a variety of display setups. In particular, user performance is investigated in terms of menu selections in circular and rectangular pop-up menus using stylus-driven direct input on horizontal and vertical display surfaces. These studies help to clarify effects of hand posture and hand preference. The results of these studies show that both left-handed and right-handed users demonstrate a consistent, but mirrored pattern of selection times that is corroborated by qualitative measures of user preference. This pattern is different for both vertical and horizontal displays due to a change in hand posture. Implementation details are provided for an automatic menu placement strategy for a tabletop display. Details are presented on how to detect which hand is being used to hold the device and on how to apply the results of the study to display rectangular pop-up menus in a co-located collaborative environment.