Consistency and simplicity are key words for a user-friendly terminal. There are several guidelines of good design and layout of information. Visual information should be supplied by audible and vice versa. User instructions should be based on the requirements for those who actually need them, i.e. seldom users, tourists, children and elderly. Touchscreens Touchscreens are becoming increasingly used on public terminals, especially where the terminal has so many functions and services that it is not feas-ible to have them provided by discrete buttons.
Touchscreens are very difficult or impossible to use by visually impaired persons.
The user slides a finger about on the screen. When the finger touches the edge of a button, a click sound is heard, and when an object is entered, the verbal name of the object is presented. The button is then activated with a separate dedicated button. To allow individuals who have artificial hands or arms or prosthetic hooks to use the screen it is important that the touchscreen do not require that it is touched by a human body. Contactless cards There are transmission technologies, for example infrared technologies, which can be used in card systems to allow the use of the card at a distance, i.e. contactless cards.