User interface is the first impression of a software system from the user’s point of view. Therefore any software system must satisfy the requirement of user. UI mainly performs two functions − Accepting the user’s input Displaying the output Users will initially see the architecture of software system’s external user interface without considering its internal architecture.
A graphical user interface is the most common type of user interface available today. It is a very user friendly because it makes use of pictures, graphics, and icons - hence why it is called 'graphical'. It is also known as a WIMP interface because it makes use of − Windows − A rectangular area on the screen where the commonly used applications run. Icons − A picture or symbol which is used to represent a software application or hardware device.
It starts with task analysis which understands the user’s primary tasks and problem domain. It should be designed in terms of User’s terminology and outset of user’s job rather than programmer’s. To perform user interface analysis, the practitioner needs to study and understand four elements − The users who will interact with the system through the interface The tasks that end users must perform to do their work The content that is presented as part of the interface The work environment in which these tasks will be conducted
Interface analysis It concentrates or focuses on users, tasks, content, and work environment who will interact with the system. Defines the human - and computer-oriented tasks that are required to achieve system function. Interface design It defines a set of interface objects, actions, and their screen representations that enable a user to perform all defined tasks in a manner that meets every usability objective defined for the system. Interface construction It starts with a prototype that enables usage scenarios to be evaluated and continues with development tools to complete the construction. Interface validation It focuses on the ability of the interface to implement every user task correctly, accommodate all task variations, to achieve all general user requirements, and the degree to which the interface is easy to use and easy to learn.
