In the evironments such as cellular phones and networked home appliances, it is difficult to select objects on a screen (icons, hyper links, etc.). because general pointing devices(mouse, trackball, etc.) are not available. PartNavi enables object selection with a few button operations in those evironments.
Our approach is to divide a screen into areas that correspond to buttons arranged in 3x3 matrix. These areas are recursively divided when the corresponded button is pressed. The screen zooms into the selected area. And an object is selected when the object is the last object in the selected area.
Compared with the conventional navigation using cursor keys, the method provides faster navigation especially when many targets exist. Moreover, this method is effective to browse webpages in small screens without loosing original appearances designed for computer screen. A preliminary usability study with a prototype system shows that our method can improve the performance of object selection on a small screen.