The user interface is the level of communication between humans and computers. There are two levels of depth: sensory and emotional. The sensing level refers to the visual, tactile, and auditory levels between humans and machines. The emotional level refers to the rapport between humans and machines as a result of communication. In a word, the user interface design is human-centered, which makes the product easy to use and pleasant to use.

The workflow of user interface design

The workflow of user interface design is divided into three parts: structure design, interaction design, and visual design.

· Structure Design

Structural Design, also known as Conceptual Design, is the skeleton of interface Design. Develop the overall architecture of the product through user research and task analysis. Paper-based, low-fidelity prototypes can be tested and refined by users. In the structural design, the logical classification and word definition of the catalog system is the important prerequisites for users to understand and operate easily. 

· Interactive Design

The purpose of interaction design is to make the product easy for users to use. The realization of any product function is achieved through the interaction between humans and machines. Therefore, the human factor should be embodied as the core of the design. The principles of interaction design are as follows: 

1) Clear error message. After misoperation, the system provides targeted hints.

2) Let the user control the interface."Next step", "complete", facing different levels to provide a variety of choices, to provide different levels of users with a variety of possibilities.

3) Allow the use of both mouse and keyboard. In the same function, you can use a mouse and keyboard at the same time. Offers a variety of possibilities.

4) Allow work interruptions. Example: when you write a new text message on your cell phone, you receive a text message or call, and when you come back, you can still find the new text message you just wrote.

5) Use the user's language, not the technical language.

6) Provide quick feedback. Give users psychological hints to avoid anxiety.

7) Convenient exit. Such as the exit of the phone, is to press a button to exit completely, or layer by layer exit. Two possibilities are offered.

8) Navigation function. It's easy to jump from one function to another by moving functionality over time.

9) Let the user know his/her current location and make him/her decide on the next action.

· Visual Design

On the basis of structural design, visual design is carried out by referring to the psychological model and task achievement of the target group. Include color, font, page, etc. Visual design should achieve the purpose of user pleasure. The principles of visual design are as follows:

1) Clear and clear interface. Allows users to customize the interface.

2) Reduce the burden of short-term memory. Let the computer help to remember, for example, User Name, Password, IE into the interface address can let the machine remember.

3) Rely on cognition rather than memory. Such as print icon memory, drop-down menu list selection

4) Provide visual cues. Visual stimuli of graphic symbols; GUI (Graphical interface Design): Where, What, Next Step

5) Provide the functions of default, undo and redo

6) Provide shortcuts to the interface

7) Use real-world metaphors whenever possible. Such as telephone, printer icon design, respect the user's previous experience.

8) Improve visual clarity. Be well organized; Don't let users guess the layout and metaphor of pictures and words.

9) Interface coordination and consistency.If the mobile phone interface button emissions, the left button affirmation; Right-click negation; Or by content.

10) Same function with the same graphics.

11) Color and content. The overall software should be no more than 5 color systems. Try to use less red and green colors. The approximate color indicates the approximate meaning.