Abstract: Direction may have an effect on the performance of pen pressure in pointing tasks,but the impact factor is not considered in Fitts’ Law．To investigate whether directions have an influence on the performance of the pen pressure in pointing operations,we designed the experiment which contains two kinds of directions．One is made up of four rectangular menus with different directions (North-South,West-East,Northeast-Southwest and Northwest-Southeast).The other is pressure direction.The participants increase pen pressure or decrease pen pressure to select the targets on the rectangular menu,and we refered to as PI Pointing and PD Pointing,respectively．Twelve participants are required to obtain and select two targets which have different distances (100,200,300 pixels) and different widths (20,30,40 pixels) on rectangular menus．Experimental results show that the pressure direction has an impact on pressure efficiency,while the different menu directions have no significant effect．The findings of this study will be useful for human-oriented pen pressure use in user interface designs.

Key words: Pointing tasks,Pressure performance,Direction effect,Pen-based interfaces