The human computer interface is what allows the user to communicate with the computer and is often called simply the user interface.
The three main types of user interface are;
- Menu-driven ;
- Graphical or GUI.
Menu-driven user interfaces
- Menu-driven systems offer the user lists of options which they can select by pressing a particular key on the keyboard.
- The main advantage of menu-driven systems is that they are easy to use.
- The main disadvantage of menu-driven systems is getting to one particular option can often involve working through many different menu screens.
Command-driven user interfaces
- To use a command-driven system to communicate with the computer, the user has to type in special command words. DOS, which stands for Disk Operating System, is a very commonly used command-driven user interface.
- The main advantage of command driven interfaces is that they can be quick to use as long as the user knows the correct commands.
- The main disadvantage of command-driven interfaces is that they are very difficult to use if the user is a beginner or doesn’t know the correct commands.
- Command-driven systems can be very unfriendly and confusing for non-computer experts to use.
Graphical user interfaces
- The most widely used type of graphical user interfaces are WIMP systems.
- WIMP stands for Windows Icons Menu Pointer.
- Options are represented by small pictures or 'icons' arranged inside rectangular boxes called windows.
- The main advantage of graphical user interfaces is that they are very easy to use, especially for a beginner.
- The main disadvantage is the amount of memory space they need. A graphical user interface needs a lot of RAM to run properly and takes up a large amount of hard disk space.
User interface design
A good user interface should be;
- User-friendly; Consistency in operation, screen layout etc;
- Colours should be chosen carefully e.g. that are easy to see;
- Sound can be used to do things such as alerting the user to problems but it should also be possible to turn it off;
- On-line help is often a useful feature