Interaction - the exchange of actions and reactions to these actions between the computer and the user. A few years ago the main type of interaction was the text (the so-called terminal or command system). Currently, the interaction can also include graphics and icons (signs) instead of text, but to describe the process of interaction still use text.
There are a number of styles of interactions, which are divided into two main types. The first is the use of the interface command language - the command input text means; and the second is direct manipulation. Thus, there are a number of ways in which the user could communicate with the computer:
Command language - the user controls the system by entering appropriate commands in a test mode;
Question and answer dialogue, where the computer asks questions and the user responds to it (or Vice versa);
Form - the user fills the form or dialog fields, entering data in required fields;
Menu - the user is provided with a number of options and controls the system by selecting the relevant points;
Direct manipulation - the user manipulates objects on the screen through the device of manipulation, such as a mouse. Another term for direct manipulation interface - a Graphical User Interface.
In the I & C systems of railway transport to date, usually use combined styles of interaction from above.
The purpose of the programmatic interfaces is to display information as efficiently as possible for human perception and to structure the display so that to draw attention to the most important pieces of information. The main objective is to minimize the total information on screen and present only what is necessary for the user.
When creating human-machine interfaces required to use these core principles:
1. The natural (intuitive)
The system should not cause the user difficulties in finding the necessary directives (interface elements) to control the process of solving the task.
2. Consistency
If in the process of working with the system by the user have been used some techniques work with some part of the system, in another part of the system work must be identical. Also work with the system through the interface must conform to the usual standards (e.g. use of Enter key).
3. Neizbezhnost
This means that the user needs to enter only minimal information to operate or manage the system. For example, the user must enter non-digits (00010 instead of 10). Similarly, you cannot require the user to enter information that was previously entered or which can be automatically obtained from the system. It is desirable to use default values where possible to minimize the process of entering information.
4. Direct access to the help system
In the process, it is necessary that the system provide the user with the necessary instructions. The help system answers the three basic aspects - the quality and quantity of provide of the teams; the nature of the error messages and confirm that the system does. Error messages should be useful and user-friendly.
5. Flexibility
How well the system interface can serve user with different levels of training? For inexperienced users the interface can be arranged as a hierarchical menu structure, while advanced users as commands, combinations of keystrokes and options.