The role that machines play in the human experience continues to evolve. While being both the masters and developers of technology, many times individuals feel as though they are controlled or limited by the machine, because the thought processes of one human do not easily translate via the machine interface to others. What seems logical and intuitive to the programmer / developer is typically completely lost on the novice user. The question of "What do I do now?" is all too typical of a new user while staring at an unfamiliar display on the screen.
Although the keyboard itself has evolved very little over the past 100 years, its very ubiquity and integration into human society makes it a viable approach to text and character entry. Many different approaches have been made to try and make the keyboard a more effective input device, but the familiarity and pervasiveness of the standard "QWERTY" layout (named for the letters across the top row) continues to be the standard for both new and accomplished computer users. There is truth to the fact that the original layout that still exists today was to prevent the user from typing too fast on the original mechanical typewriters so that the levers would not conflict with each other. There is also truth to the fact that the layout allowed early typewriter salesmen to type "typewriter" easily by placing those keys along the top row!
Because of this familiarity and the inescapable delays in realizing other technologies, the on-screen keyboard is a natural extension of the physical keyboard. Any touch-typist will quickly realize the difficulty of using a virtual keyboard in a non-familiar layout (such as ABC, or the Dvorak layouts). Even though technology can astound and amaze us, we are still rooted in our pasts and tied to our education and training experiences.
The power of the Graphical User Interface (GUI), pointing devices, and voice-recognition / commands is acknowledged, but as is always the case, there are situations that present a non-ideal environment for the use of these advanced technologies. High-noise environments such as the factory floor and speaker dependence prevents voice interfaces from being the cure-all to the HMI. Security issues such as passwords and logons also defeat the voice interface as being ideal for every situation. Saying your password aloud to a speaker independent system can easily defeat the underlying needs of a secure system.
Because of the limitations of each input device, the enhancement of each device has been a common theme in addressing the needs of each type of user. Windows has evolved into a multi-faceted interface that allows complete control via the pointing device, or complete control from the keyboard. The on-screen virtual keyboard presents a familiar and natural extension of the pointing device's need for quick character input (number of copies to print, password, name, etc.). When the pointing device itself is a Touchscreen or Pen, this intuitive extension of providing the facility of a virtual keyboard adds powerful capabilities in making these pointing devices the PRIMARY input device.