The human-computer interface

The human-computer interface

1. GUI (wimp)Graphical User Interface

   • Advantages
     • This type of user interface is easy to use, especially for a beginner
     • It is easy to explore and find your way around the system using a WIMP/ GUI interface
     • You do not have to learn complicated commands
     • There are usually a reasonable 'help' system included with WIMP interfaces
     • They let you exchange data between different software applications
     • You get the benefits of WYSIWYG (what you see is what you get)
   • Disadvantages
     • GUIs take up a much larger amount of hard disk space than other interfaces
     • They need significantly more memory (RAM) to run than other interface types
     • They use more processing power than other types of interface
     • They can be slow for experienced programmers to use. These people often find CLI interfaces much faster to use

2. Menu driven interface

   • cash mashine for example
   • Advantages
     • There are no commands to learn or remember
     • Extremely easy to use. Someone who has never seen the interface before can work out what to do
     • Step-by-step options are given so that the user doesn't have to remember anything
     • Menu interfaces don't have to be visual, they can be spoken - good for telephones or for visually impaired people
     • They don't need huge amounts of processing power or memory
   • disadvantages
     • A poorly designed menu interface may be slow to use
     • It can be irritating if there are too many menu screens to work through
     • You often can't go to the exact place you want right at the start. You have to work your way through the menu screens even if you know where you want to get to.
     • If the menu is poorly designed it might be hard to read

3. command line interface

   • disadvantages
     • For someone who has never used a CLI, it can be very confusing
     • Commands have to be typed precisely. If there is a spelling error the command will fail
     • If you mis-type an instruction, it is often necessary to start from scratch again
     • There are a large number of commands which need to be learned - in the case of Unix it can be hundreds
     • You can't just guess what the instruction might be and you can't just 'have a go'.
   • Advantages
     • If the user knows the correct commands then this type of interface can be much faster than any other type of interface
     • This type of interface needs much less memory
     • A low resolution, cheaper monitor can be used with this type of interface
     • A CLI does not require Windows to run

4. speech and sound

   • disadvantages
     • Reliability remains an issue - the interface can only respond to commands that have been programmed
     • A voice interface might need training in order to get the software to recognise what the user is saying
   • advantages
     • Suitable for physically handicapped people
     • More flexibility than a dialogue interface
     • The user does not need to be trained in how to use the interface

5. touch sensetive interface

   • advantages
     • Do not need good ICT skills such as typing to be able to use
     • Most touch screens are fixed to a larger device so there is less chance of them being removed, lost or stolen (unlike keyboards)
     • Can be adapted for many uses e.g. cashpoint machine, shop, ticket sales office, garage
   • disadvantages
     • Need to understand the language or the meaning of the icons
     • If the screen becomes damaged it might not pick up the touch command
     • The screen could become scratched or dirty so it is difficult to see the options available
     • No so good in bright sunshine as the screen is hard to see

6. Bimetrics means to measure and analyse physical characteristics to correctly identify people.

   • FIngerprints
   • voice patterns/;recognition
   • eye scanner(retina)
   • facial expressions
   • palm prints

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