The remarkable progress since 1960 in computer processor speeds and storage
capabilities has been matchedby improvements in many input/output devices.
Ten-character-per-second Teletypes have been replaced by high-speed mega¬
pixel graphical displays for output. Although the common Sholes or QWERTY
keyboard layout is likely to remain the primary device for text input, novel
strategies have emerged to meet the needs of mobile device users. Pointing
devices, especially the mouse and touchscreen, free users from keyboards for
many tasks. The future of computing is likely to include more gestural input,
two-handed input, three-dimensional pointing, voice input/output, wearable
devices, and whole-body involvement for some input and output tasks.
Pointingdevices have undergone hundreds of refinements to accom