human computer interface

human computer interface

1. GUI (wimp)

   • advantages
     • easy to use, especially for a beginner
     • easy to explore and find your way around the system
     • do not have to learn complicated commands
     • usually good help facilities provided with WIMP interfaces
     • get the benefits of WYSIWYG
     • let you exchange data between different software applications
   • A GUI (pronounced gooey) is also known as a WIMP interface
   • windows, icons menus, pointers
   • disadvantages
     • GUIs take up a much larger amount of hard disk space than other interfaces
     • use more processing power than other types of interface
     • can be slow for experienced programmers to use. These people often find CLI interfaces faster to use
     • need significantly more memory (RAM) to run than other interface types

2. command line

   • advantages
     • If the user knows the correct commands then this type of interface can be much faster
     • less memory (RAM) in order to use compared to other types of user interfaces
     • does not use as much CPU processing time as others
     • A low resolution, cheaper monitor can be used with this type of interface
     • A CLI does not require Windows to run
   • 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
     • large number of commands which need to be learned

3. menu driven interfaces

   • advantages
     • Extremely easy to use
     • There are no commands to learn or remember
     • Step-by-step options are given so that the user doesn't have to remember anything
     • Even if you don't know what to do, you can usually guess your way around the options
     • 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
     • If the menu is poorly designed it might be hard to read
     • You often can't go to the exact place you want right at the start
     • The menu can take up a large part of the screen so you have to keep flicking back and forwards between applications

4. speach and sound

   • 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
   • disadvantges
     • Reliability remains an issue - the interface can only respond to commands that have been programmed
     • Not widely available as other forms of interface are often superior
     • Highly complex to program and so only warrants this kind of interface where other types of interface are unsuitable
     • A voice interface might need training in order to get the software to recognise what the user is saying

5. touch sensitive

   • advanatages
     • You can see all of the options available
     • Intuitive to use
     • 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
     • Only limited options can be offered
     • If the screen becomes damaged it might not pick up the touch command