SlideBar: Analysis of a linear input device
Behavior and Information Technology
The SlideBar is a physical linear input device for absolute position control of one degree of freedom, consisting of a physical slider with a graspable knob positioned near or attached to the keyboard. Its range of motion is directly mapped to a one dimensional input widget such as a scrollbar. The SlideBar provides absolute position control in one dimension, is usable in the non-dominant hand in conjunction with a pointing device, and offers constrained passive haptic feedback. These
... ck. These characteristics make the device appropriate for the common class of tasks characterized by one-dimensional input and constrained range of operation. An empirical study of three devices (SlideBar, mouse controlled scrollbar, and mousewheel) shows that for common scrolling tasks, the SlideBar has a significant advantage over a standard mouse controlled scrollbar in both speed and user preference and an advantage over the mousewheel in user preference. BACKGROUND Personal computers have come to be so popular largely because they are multi-function devices. They consist of general-purpose processors, general-purpose input devices, and general-purpose output devices. This is a fundamental design feature of today's personal computers, and it works remarkably well. However, this design represents one side of a trade-off that results in a computer that can do many tasks well, but does not necessarily do each individual task as well as a specialized device could. Certain very common tasks, such as scrolling, are a case in point. It is no surprise then, that design, implementation and evaluation of scrolling mechanisms and pointing devices are well-studied areas. Scrolling is one example of a common class of computer input tasks characterized by having one dimension of freedom and a constrained range of operation. Some other examples are selecting from menus, zooming in and out of documents and operating onscreen widgets, e.g., slider widgets. Even if there is not an explicit mouse controlled widget, the task can still exist and in current applications is often controlled via keyboard or with specific selections from menu items. For instance, photo browsing applications commonly have a menu for controlling the magnification with common values such as 50%, 100% or 200%, or in specific modes, the user may increment or decrement at predefined values with a mouse click, giving limited control of a task that actually has a smooth, broad range of input values. Since this common class of tasks is broad and well defined, it seems logical to consider an input device tailored specifically for this purpose. In this paper, we introduce the SlideBar, a linear input device for absolute position control, which we built with the intention of providing users with an input device better suited for linear tasks. We delve into the reasons we expect this device to be well suited for linear tasks and give the results of a study comp aring it to common input devices for the specific linear task of scrolling.