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Human Computer Interface
An interface is where one object meets another. When designing a computer system, consideration has to be given to how a person will interact with a computer. There may be a number of design factors...
  • what is the workplace like? ..noisy? dirty? busy?
  • what are the IT skills of the users like?
  • security considerations

These are the main types of user interface:

Command A user has to type in a command.

An expert user can generally do this quickly and can tailor a command to exactly suit requirements.

Example : DOS is a command line interface

To get a list of all files on a floppy disc, a user would type:
DIR a:

To print the list across the screen rather than down he would type:
DIR a: /w

Batch files of a number of these commands may be created.

A disadvantage to this type of interface is that a user will need to learn the commands and spell/type them in correctly.
Menu Commands/Options are displayed as a hierarchy of (drop-down) menus...selecting one menu option may lead to another menu and so on...

There is no need to learn commands but a user would need to understand the terms in the menus, and it can be quite difficult sometimes to find the exact option you want ... especially if it is an option in a submenu of a submenu of a submenu!

Example: Most Windows applications have a menu bar at the top.

GUI - Graphical User Interface Small pictures (icons) are used to represent selections and a user would click on them with a mouse pointer. These are usually combined with a system of menus.

Sometimes called a WIMP (Windows, Icons, Menus and Pointers) environment.

Example: Microsoft Windows is an example of a GUI

Advantages :

  • No great level of IT skill needed
  • Easily recognisable and understandable icons lead to fast selection
  • Identical icons can be used in a number of applications - so learning to use them is easier.
  • No need to learn any difficult commands
Speech recognition Microphones are used to input spoken commands. The sound pattern is analysed and the command is carried out.

Useful for situations where computer users may not have free hands - surgeon, car driver, fighter pilot.

Important use is for handicapped.
Handwriting recognition Often used on small computers where keyboards are not practical.

The user writes on the screen using a stylus and the software converts into text.

 
Hypertext Hyperlinks are used to navigate from one page to another. Useful for users with low-level IT skills.

Example : Internet web pages.