A Study Of Deformable Cursor On Multi-Touch Devices

Hunting for better target pointing(or selection)techniques is always an essential research topic in HCI,since target pointing(or selection)is the most important and basic task in GUIs.A cursor typically works as a visual widget in pointing or selection tasks.There are more and more studies for target pointing(or selection)techniques on multi-touch screens with the popularity of virous multi-touch devices.Direct Touch(DT)technique is the most widely used because of its fast,simple,convenient,and natural features.However,there are still some drawbacks with DT,e.g.,target accessibility,visual occlusion,pointing accuracy,and low performance for multiple selection.We propose a Deformable Cursor(DC)technique for multi-touch screens to eliminate the drawbacks.A user can manipulate the size,shape,location,and direction of a DC.The research includes two experiments presented as follows.A pilot study was executed to determine a DC's optimal parameters,i.e.,the Cursor Type(CT),Ratio of Functional Area of Cursor(RFAC),and Targets Acquisition(TAC).The result shows that the optimal values of CT,RFAC,and TAC are Two Points Rectangular Cursor,100%,and Ratio of Target Area covered by the cursor,respectively.A comparative experiment was done to quantitatively compare DC and DT regarding target selection time,error rate,and users' subjective preference.The experimental result shows that the error rates of DC are much lower than those of DT in all cases.DC significantly outperformed DT in the mean overall selection time and multiple selection time,but DT consumed significantly less time in single target selection tasks.DC eliminates the drawbacks of target accessibility,visual occlusion,low pointing accuracy for small targets,and low performance for multiple selection.The subjective survey shows that most participants preferred DC for it is more suitable for complex and tedious multiple selection tasks.