1.6

1.6

1. HCI

   • Text based interface
     • Input to the computer is via text
     • Adv: Requires fewer resources
     • Adv: Very efficient for an experienced user
     • Dis: Likely to take a novice a longer time to learn
   • Graphical user interface
     • Most communication is via elements such as windows, icons, menus and pointers.
     • Adv: GUI system is easier to learn
     • Adv: GUI system usually more intuitive
     • Adv: It is easier to/you have the ability to copy and paste between applications
     • Dis: Uses more computer resources
   • Speech recognition
     • Commands and text input are given to the computer via human speech
     • Adv: May be faster than typing
     • Adv: User can be doing something else with their hands
     • Adv: Can be used by someone who is disabled
     • Dis: Uses more computer resources
     • Dis: Can have difficulty with homophones e.g. weather and whether
     • Dis: Depends on environment. If loud, bad. If quiet, good
     • Ambiguity
       • Homophones
       • Command words may be mistaken as input words
       • It is an uncertainty of meaning where different interpretations are possible
       • Accents
       • Voice patterns
       • Using slang or unregistered words
   • Speech synthesis
     • Used for telephone banking
     • Adv: Useful for people with visual impairment
     • Dis: Can be annoying
     • Dis: Uses more computer resources
   • Handwriting recognition
     • Data is entered by a stylus/pen on a pad
     • Adv: Quicker/easier for user than typing
     • Adv: Avoids bulky keyboard
     • Dis: May not be very accurate
     • Dis: Difficult to use. Needs constant visual checking.
   • Touch input
     • Adv: No need for pointing device like stylus
     • Adv: Intuitive and easy for beginners
     • Can pinch/scale text/image

2. Natural interface

   • A natural user interface relies on intuitive actions related to natural, everyday human behaviour
   • Examples: Touch screen where user taps graphic icons
   • Example: Gesture recognition system which tracks and translate user movements into instructions
   • Speech recognition system: Identifies spoken words and phrases and converts them to instructions

3. Design validation/review

   • Check the correspondance between the actual design and its specification
   • Confirm that the most appropriate techniques have been used
   • Confirm the HCI is appropriate
   • A review of the design is undertaken to ensure:

4. Design Evaluation

   • When deciding whether a system is good, the following should be checked.
   • Requirements - does it meet them all
   • Performance - does the solution work as quickly as expected
   • Robustness - a word processor can fail but air traffic can't
   • Cost - is it on budget
   • Usability - is it usable by the targeted user

5. Immersive interface

   • This places one or more of the user's senses into a computer generated virtual environment
   • Example: Virtual reality headsets
   • Example: Forced feedback from vibrations
   • Example: 3D earphones