Human Computer Interface

Human Computer Interface

1. Definition:

   • HCI- the point of interaction between people and computer systems

2. 6 Things which affect the type of interface you will build for a user:

   • Experience of user- expert requires less help
     • children's paining programme should be easy to use
     • Benefits:
       • Level and layout suits experience of child
       • Limited text
       • Minimal icons
       • Mouse control for drawing
   • Needs of users
     • Some users may not be able to use QUERTY keyboard
     • Disabled users interface
       • E.G. Stephen Hawkins
   • Preference of user- how to input data
     • Some users may want to change preferences
     • These are costly and complicated to implement
   • Environment- must be suited to enviromnt
     • Public kiosk inteface
       • Benefits:
         • Touch sensitive screens are easy to use
         • Visual clues are easy to select
         • No QWERTY keyboard to vandalise
         • Limited input options
         • Easy for OAP's
   • Task to be undertaken
   • Resources avaliable

3. Command line interface

   • DOS
     • A prompt on screen to show where the next command is entered
     • Text only input
   • Advantages
     • User has flexibility to choose what they want to type
     • Faster execution as cpu had less to do to support interface
     • Minimal input/output devices
   • Disadvantages
     • Hard to learn
     • Ammount of typing
     • Cant use graphics

4. Graphical User Interface

   • Uses mouse and clicks on buttons & toolbards
   • Intuitive- not based on language- suited to international use by different language speaking peoples
   • Provides shortcuts to often used functions; so tasks are carried out more efficiently
   • Configurable
   • Hides irrelevant info, e.g. menu commands
   • Windows software:
     • GUI's present a more intuitive interface for the user, enabling novice users an easy way to use a computer system
     • Benefits
       • Intuitive- Easy to learn
       • Graphical- includes pictures
       • Uses logos to assist memory
     • Problems
       • Needs a fast computer with a lot of RAM
       • Heavy use of machine resources, E.G. Hard disk space, Memory space
   • WIMP
     • W- Windows
       • Applications are viewed through rectangular frames called windows
     • I- icons
       • Picture icons are used for common tasks such as printing and saving. These icons are quicker to use than written commands
     • M-menu
       • Menus display a pre-set list of commands. Many menus in a GUI are presented in pop-up menu of pull down menu
     • P- pointer
       • a pointing device, usually controlled by a mouse, is displayed on the screen

5. Natural language interface

   • interface where you can speak or type a sentance