Studies on touch screen mainly focus on modalities of input, but the effect caused by environmental parameters has not been studied seriously. In this paper, we designed two experiments that can be used to investigate: whether pen-based input operation can be affected by tilt angle of touch screen, and at which tilt angle of touch screen can user do input operation with comfort, quickness, and accuracy. The experiments we designed include pointing tasks (1-dimensional and 2-dimensional) based on Fitts’ law and stroking tasks (linear and circle) based on Steering law. Each task would be done under 6 kinds of tilt angle of touch screen: 0, 15, 30, 45, 60 and 90 degrees.

In this paper, we designed two experiments that can be used to investigate: 1) whether pen-based input operation can be affected by tilt angle of tablet; 2) at which tilt angle of tablet can user do pen-based input operation with comfort, quickness, and accuracy. The experiments include pointing tasks (1-dimensional and 2-dimensional) based on Fitts’ law and stroking tasks (linear and circle) based on Steering law. Each task would be done under 5 kinds of tilt angle of tablet: 0, 15, 30, 45, and 60 degrees.