Monday, 8 September 2014

Program design and UI

08/09/2014 (Mon)

3 Key stages to program design:
-          Designing the User Interface
-          Designing the Data
-          Designing the Processing (algorithms)


User interface:
The method where the user tells the device what to do and the device responds.
The difference in UI changes and updates between mobile phones and ATMs is largely to do
with competition. There is no competition between brands of ATMs, however, UI is unique
selling point of many mobile phones. ATMs also have to have familiarity, so that anyone can
use an ATM anywhere in the world.

Types of interface:
1. Command Line Interface (CLI)
 - Linux terminal
 - Command prompt (Windows)
 - PowerShell (Windows)
 - Mac terminal (AT&T UNIX - FreeBSD)

2. WIMP - Menu Driven (Windows Icons Menus and Pointers)

3. Natural Language - Voice recognition technologies - Google search

4. Graphical User Interface



Command Line Interface
-          Purely based on command sets
-          Difficult to learn - Acronym commands that can be chained, hypothetically unlimited commands
-          For technical people.
Command line can be powerful and efficient, such as assigning values to multiple computers.

Menu Driven
-          Easy to use
-          Require little technical knowledge
-          Limited to the options available
-          Examples are Sat Nav systems, old phones, Sky remotes, ATM.

Natural Language
-          “Hello computer, create a spreadsheet with income and expenditure to calculate my monthly outgoings…”
-          Difficult to construct – Human language is very ambiguous
-          AI of computer systems is not developed enough
-          Is used to some extent in Sat Nav car systems.

GUI
Advantages:
-          Commonly used
-          Easy to learn
-          Require limited training
-          Intuitive
-          Fewer mistakes can be made when using the program
-          Use of GUI objects such as drop downs, option buttons, dialogue boxes to alert on validation errors
-          User can associate icons with real world objects – e.g. Filing cabinet and recycle bin.
Limitations:
-          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.



Factors to consider when designing a user interface:
-          The user
-          Screen layout
Most important functions are central, with more complex or less used functions in menus
-          Validation
Asks if you’re sure – Checks spelling, lets you know you need an @ symbol for your email address, make sure the username is free, date of birth in reasonable range etc.
-          Online help
-          Readability
-          Choice of fonts and colours
-          Technology Platform
-          Help
Windows paperclip man – ‘What would you like to do?’

Windows 8
Windows 8 was redesigned radically, with the new tile based start menu that is completely different to its predecessor. The changes were made partly to shift closer to touch screen devices, such as tablets.
Microsoft seemed to believe that tablets and PCs needed to be combined – but there was no demand. They attempted to create demand with tablet PCs and surface, which also only partly worked.
One detail that was a controversial change was the removal of the start button in the bottom left corner – it was replaced in windows 8.1, but it was unnerving for long term users used to utilizing the start button for the control panel, browse files, and generally use as the first call for system functions.
Windows 8 was received so poorly largely because of the steep learning curve, although these complaints were addressed with Windows 8.1, an update to edge towards the functionality of Windows 7. A desktop mode was also implemented, to actually avoid using the tile system in place.
Windows 8 also most likely failed because it seemed to alienate long term desktop users with a useless interface. For experienced users, the interface got in the way more than it sped things up, especially without a touch screen.







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