2d Human-Computer interfaces

2d Human-Computer interfaces

1. Command Line Interfaces

   • Advantages
     • O - Requires very little memory
     • O - Less processing time
     • O - Can be used for simple to complex instructions
     • O - No restrictions to commands in pre-determined lists
     • O - takes little time if user is a pro
   • Disadvantages
     • X - No margin for spelling errors
     • X - User needs to memorise commands
     • X - Time consuming to enter lots of data
   • Used for complex tasks such as configuring embedded systems and things not usually needing an interface
   • Uses prompts to aid user know what to type and feedback after successful actions
   • User types commands

2. Menus/Submenus

   • Advantages
     • O - Users presented with commands rather than memorising
     • O - Text based, doesn't need as much memory as GUI
     • O - Menu can be provided in context to what the user is doing
   • Disadvantages
     • X - Users restricted be pre-defined list of commands
     • X - May have to navigate many sub-menus to get command you want
     • X - Some menu options don't correspond to an obvious action.
   • Provide simple list of choices for user to select to either perform an action or open another menu
   • Usually text based
   • Can have numbered or lettered options
     • Lettered options may have more meaning but can lead to over lapping
   • Can use arrow key or pointing device to highlight and select options
   • Needs meaningful and structured system

3. Graphical User Interface

   • Advantages
     • O - Simple to understand due to various prompts such as pictures, icons and menus
     • O - More intuitive and can be tailored to users' mental models
     • O - Good for visual learners.
   • Disadvantages
     • X- Uses a lot of memory
     • X - Requires a lot of processing
   • Contains some elements of WIMP but not necessarily all
   • Very common

4. Natural Language

   • Advantages
     • O - No learnt commands
     • O - Voice can be quicker than typing
     • O- Can be used with no hands available.
   • Disadvantages
     • X - More processing needed to pick key words from complex sentences
     • X - Need good voice recognition to process different voices
     • X - Difficult to give complex computer based commands
   • Uses everyday language rather than specific computer based commands
   • Computer responds in everyday, conversational language.
   • e.g. voice command interfaces, siri

5. Form dialogue

   • Advantages
     • O - Clear prompts means less likely to make mistakes
     • O - Controls used to aid selection
     • O - Can be validated
     • O - New options given of removed based on previous responses
     • O - Can give default options
   • Disadvantages
     • X - Restrictions to options on screen
     • X - A lot of data entry may be frustrating
     • X - May accidentally leave given default options unchanged
   • The computer output separate prompts and response fields for a number of inputs
   • e.g. dialogue boxes