User Interface

What is User Interface?

Google = 'The means by which the user and a computer system interact in particular the use of input devices and software'

Tech Target = 'In IT the user interface is everything designed into an information device with which a person may interact with. This can include display screens, keyboards, a mouse, and the appearance of a desktop. It is also the way through which a user interacts with an application or a website. The growing dependance of many companies on web apps and mobile apps has led to many companies to improve UI.' 

Types Of User Interface -

Direct manipulation interface - General class of UI which allows users to manipulate objects which are presented to them, using actions that reflect to those of the physical world.

Graphical User Interfaces - GUI accept input via devices such as a computer keyboard and mouse and provided articulated graphical output on the computer monitor. There are at least two principles which are used in GUI design, Object orientation UI's (OOUI's) and application orientated interfaces.

• Primary methods used in the interface design include prototyping and simulation.

• Typical human - machine interface design consists of the following stages : interaction specification, interface software specification and prototyping.
• Common Practices for interaction specification include user centred design, persona, activity oriented design, scenario based design, resiliency design.
• Common Practices for interface software specification include use cases, constrain enforcement by interaction protocols (Intended to avoid user errors)
• Common practices for prototyping are based on interactive design based on libraries of interface elements (Controls, decoration etc.)

All Great interfaces share some similar or the same characteristics. 

1. Clarity - The interface avoids ambiguity by making everything clear through language, flow hierarchy and metaphors for visual elements.
2. Concision - Make the interface concise, interfaces which apply labels to every interaction makes the user experience more.
3. Familiarity - Certain elements of an interface will always be recognisable even if it is the first time a user enters a website. Real life metaphors can be used to communicate meaning.
4. Responsiveness - A good interface should not feel sluggish. This means the interface should provide good feedback to the user about whats happening and wether the users input is being successfully processed.
5. Consistency - Keeping your interface consistent across the application is important because it allows users to recognise user patterns.
6. Aesthetics - while you don't need to make an interface attractive for it to do its job, making something look good will make the time your user spends using your application more enjoyable.
7. Efficiency - Time is money and a great interface should make the user more productive through short cuts and good design. 
8. Forgiveness - A good interface should not punish users for their mistakes but instead provide the means to remedy them.

Principle of Least astonishment-

The principle of least astonishment or POLA, is a general principle in the design of any and all kinds of interfaces. It is based on the idea that human beings can only pay full attention to one thing at any one time, this leads to the conclusion that novelty should be minimised.