When building a Graphical User Interface, designers need to decide for the intended direction when moving from one interaction element to another. Tra ditionally this decision is often taken by following the writing direction of the intended users culture. That means, in Latin script a general left-to-right direc tion or in Arabic script, a right-to-left direction. The question is open whether this approach yields the best performance or if there are better suggestions for the choice of the general direction of the interaction. In this work, the results of a long-term experiment comparing mouse-based and touch-based interaction are presented. Especially, the inuence of the two dimensional direction of the interaction is investigated. The results reveal a di er ence between mouse-based and touch-based interactions: Whereas mouse-based interaction works best with diagonal and left-to-right movements, touch-based interaction prefers bottom-up and top-down movements and punishes left-to-right movements. For touch-based interaction, a mean difference in interaction times of as much as 10.8% between best and worst case were measured.

Interaction Devices, Experimental Study, Graphical User Interfaces, Human Computer Interaction