HCI

HCI

1. HCI means human-computer interface and it is the boundary where the computer and the user meet.

2. This may be known as a user interface and it determines the way the user interacts with the computer and gives instructions about what is wanted.

3. The programmes user interfaces are designed to be as easy as possible for the user to use, and they try to make the different programs they create as similar as possible, so that users are familiar with the way they work.

4. Command-line Interface - When users type instructions using words and symbols. This was used in the early times of computing and is really only suitable for skilled ICT users, as the instructions need to be known.

   • The advantages are: Instructions execute quickly, Instructions are versatile - meaning the user can select a large number of options for each instruction, The operating system s smaller when loaded into memory.
   • The disadvantages are: You need to learn the special instructions used, If you mistype an instruction or spell it wrong, then it cannot be executed, Some commands and their options can be very complex, so high-level ICT skills are needed.

5. Menu-driven interface - This is where the users select something off of a menu. This is more user-friendly than a command-line interface as the options do not have to be remembered.

   • The advantages are: Navigation to find the option required is simple. You do not need to learn what instructions are available as they are displayed in the menu. User input is validated as only the options shown can be used.
   • The disadvantages are: Some options in a menu may not mean anything to the user. It can be difficult to find options if there are many menus and sub-menus.

6. Graphical User Interface - Small pictures are used to represent options that the user can select.

   • Modern computer operating systems use GUI which stands for graphical user interface.
   • Modern operating systems use WIMP environments: Window, Icon, Menu and Pointer.
   • The advantages are: Only a low level of ICT skills is needed for the easy-to-use, intuitive interface. There is no need to learn any instructions. Pictures are more meaningful than words, so small children or people with reading problems can use this sort of interface. You can alter the way in which a GUI displays data to suit your own circumstances.
   • The disadvantages are that it is large and complex. It can take up a lot of a computer’s resources and may run slowly.

7. Voice Interface - his is where the users speaks the command into a microphone connected to the computer. Sophisticated software analyses the voice pattern and executes the instruction given.

8. Special Devices -E.g. braille keyboards, “Concept keyboards” with overlays places on the keyboards, touch-sensitive screens, puff-suck switched and foot switches allow input for people with no arm movement.