The way that humans interact with computers is constantly changing. It seems that this change is usually spurred on by advances in technology as opposed to changes in thinking. An example is the transition from the computer mouse to touch screen devices. The first mouse prototype was developed by Douglas Engelbart in 1963 and featured in his 1968 demonstration which has come to be known as ‘The Mother of All Demos’.

Later designs incorporated a ball with the wheels against it rather than the wheels directly contacting with the surface as in Engelbart’s design. Over time mechanical mice have been superseded by optical mice which make use of photodiodes to detect movement. With miniaturisation of computers themselves came laptops which made it necessary to integrate a small pointing device into them, to do this touch pads are used. With the PDAs and early tablet computers such as the Intel Web Tablet a stylus was used for pointing. With resistive and now capacitive touch screens users need only touch the screen to interact with a device. People can now use gestures giving a wider scope for control and making it more intuitive. With technology like Microsoft’s Kinect and Leap Motion, it is conceivable that touch screens may too become obsolete.

Throughout all of this development the basic idea of controlling a specific point in a virtual space and then carrying out an action based on what that area of screen represents. The clicking on an icon to start a program, the icon isn’t the program it is merely an image on a screen yet through interfaces we create these object based metaphors. To access something we want, we us in the case of a mouse an agent that represents our focus.