user interface

3 key stages to program design:

• Designing the user interface
• Designing the data
• Designing the processing

User interface:

A mechanism that responds to inputs made by the user.

(touch; voice; gesture; button; switch; multi touch gestures) 

• computer [competitive yet consistent in most designs]
• mobile phone [competitive design]
• ATM (automated teller machine)[need consistency]
• Sat Nav [consistent for ease of use but bares in mind competitive design]

Types of Interface:

• Command Line Interface (CLI)(Linux; Windows 8; powershell windows; UNIX; DOS)
• Menu Driven (cursor)
• Natural Language (Attempt to make sense of natural language)
• Graphical User Interface (GUI)

Command Line Interface:

Disadvantages:

• Purely based on command sets.
• Difficult to learn.
• Technically orientated systems.

Advantages:

• Speed.
• Richer command sets.

Menu Driven(,e.g.: Sat Nav, TV):

• Easy to use.
• Require little technical knowledge.
• Limited to the options available.

Natural Language:

• Enter commands in sentence structure.
• Difficult to construct.
• Artificial intelligence of computer systems is not developed enough.
• Is used to some extent in Sat Nav car systems.

Graphical User Interface:

• Alto completed at Xerox PARC; April 1973.

Advantages:

• Commonly used.
• Easy to learn.
• Require limited training.
• Intuitive.
• Fewer mistakes can be made.
• Use of GUI objects (,e.g.: drop downs; option buttons, dialogue boxes).
• User can associate icons with real world objects.#

Disadvantages:

• Require more processing power and system resources.
• Not always suitable for the environment it is being used in.
• Can be restrictive for more advanced users. 

Designing a user interface:

Factors to consider:

• The user.
• Screen layout.
• Validation.
• Online help.
• Readability.
• Choice of fonts and colours.
• Technology Platform (restrictions?).

Well designed user interface:

• Help.

Windows 8:

• Introduces the Windows Runtime (WinRT) platform which can be used to create Windows Store apps (commonly known as Metro-style apps).
• Task bar to the right of the screen known as 'the charms'.
• Bundled apps.
• New start screen that resembles the start screen of a windows phone.
• Search charm uses full screen display
• Account integration between Microsoft services.
• Improved support for multimedia configuration.

These changes have been made to make it consistent with other existing Microsoft product, i.e. phone, Xbox 360, Xbox one. Whilst incorporating some features from windows 7 that have proven useful, Microsoft has introduced an easy to use interface that can be associated with touchscreen tablet displays.