• User interface design helps in successing most of the software.

• It is part of the user and computer.

• Good interface design is user friendly.

Types of user interface:

1. Command Interpreter

Commands help the user to communicate with the computer system.

2. Graphical User Interfaces (GUI)

• It is another approach to communicate with system.

• It allows a mouse-based, window-menu-based systems as an interface.

The Golden Rules

The golden rules are known as interface design principles.

The golden rule are as follows:

1. Place the user in control

• The interaction should be defined in such a way that the user is not forced to implement unnecessary actions.

• The technical internal details must be hidden from the casual user.

• Design for the direct interaction with objects that appear on the screen.

2. Reduce the user's memory load

• The user interface must be designed in such a way that it reduces the demands on the user's short term memory.

• Create the meaningful defaults value as an advantage for the average users in the start of application.

• There must be a reset option for obtaining the default values.

• The shortcut should be easily remembered by the users.

• The interface screen should be friendly to users.

3. Make the interface consistent

• The system must allow the user to put task into meaningful context.

• Consistency should be maintained for all the interaction.

• Do not change the past system that is created by the user expectation unless there is a good reason to do that.

User interface design issues

The user interface design consist of following four issues:

1. Response time of the system

Length and variability are the two important characteristic of the system response time.

2. User help facilities

The user of each software system needs the help facility or the user manual for the smooth use of the software.

3. Error information handling

Many error messages and warnings are created which irritate the users as they are not meaningful. Only the critical problems should be handled.

Error message guidelines are as follows:

• The language of error message should be described in plain language i.e easily understandable for the users. For recovering the error, useful advice should be provided.

• The error message must have an audible or visual indications like beep, short flashing or the special error color.

• The error messages must indicate any negative result so that the user verifies it.

• The wordings of message should not be blamed on the user.

4. Command labeling

The commands and menu labeling must be consistent, easy to understand and learn.

WebApp Interface design

The principles for designing the WebApp are as follows:

1. Anticipation

A WebApp should be designed so that it can anticipate the user's next move.

2. Communication

The interface must communicate the status of any activity initiated by the user.

3. Consistency

Throughout the WebApp the use of navigation control, menus, icons, decorative parts should be consistent.

4. Efficiency

The design of WebApp and its interfaces must optimize the user's work efficiency and not the efficiency of developer.

5. Flexibility

The system must be flexible to accommodate the need of user.

6. Focus

The WebApp interface and the content present in it must focus on the users task.

7. Readability

The presented information must be readable to all the users.

8. Learnability

A WebApp interface must be designed to minimize the learning time.

After learned, It is necessary to minimize the relearning when the WebApp is revisited.

9. Metaphors

An interface uses an interaction metaphor that is easier to learn and use until the metaphor is appropriate for the application and the user.

10. Maintain the integrity of work product

A work product should be saved automatically so it does not lose an error message which has occurred automatically.