Understanding SC 2.5:Input Modalities
Intent
All functionality should be accessible via pointer input devices, for example, via a mouse pointer, a finger interacting with a touch screen, an electronic pencil/stylus, or a laser pointer.
People operating pointer input devices may not be able to carry out timed or complex gestures. Examples are drag-and-drop gestures and on touch screens, swiping gestures, split taps, or long presses. This Guideline does not discourage the provision of complex and timed gestures by authors. However, where they are used, an alternative method of input should be provided to enable users with motor impairments to interact with content via single untimed pointer gestures.
Often, people use devices that offer several input methods, for example, mouse input, touch input, keyboard input, and speech input. These should be supported concurrently as users may at any time swich preferred input methods due to situational circumstances, for example, the availability of a flat support for mouse operation, or situational impediments through motion or changes of ambient light.
A common requirement for pointer interaction is the ability of users to position the pointer over the target. With touch input, the pointer (the finger) is larger and less precise than a mouse cursor. For people with motor impairments, a larger target makes it easier to successfully position the pointer and activate the target.