What is a user interface? UI In Plain English

A user interface is anything that helps people control devices and programs through voice, taps, gestures, command line, and even thought. The most popular type of interface right now is the UI of applications.

UI translates to "user interface". The UI not only includes the graphical interface, but also haptic, voice or sound.

Why do we need an interface?

An interface helps two objects understand each other and exchange information.

An interface is a "communication language" understood by both objects that interact with each other to solve a particular issue.

If every app or program installed on your computer, tablet, or smartphone is a helper, then an interface is a way to communicate (interact) with it so that it helps with your business at work and in life.

For example, digital systems have user interfaces that are graphical, voice, command line, and gesture - all of which are interfaces. Through the user interface, we get access to new features that an application gives us for learning, for work, for creativity, for entertainment.

Software, hardware, and hardware-software interfaces are also common. These interfaces provide interaction not only between man and machine (device), but also between programs, hardware or computers:

• Hardware: connects two objects to each other, such as helping to connect a smartphone to a laptop using WiFi or a cable;
• Software (API): creates a connection between applications/programs, e.g. connecting one application's API to another. The most popular scenario is authorization via social networks on websites;
• Hardware-software: a combination of technical elements controlled by software.

Types of user interfaces

User interfaces come in gesture, tactile, voice, graphical, command line, and even neural.

Command Line Interface and Text Interface (Command Line Interface or CLI)

The command line is still very popular among system administrators and programmers. It is one of the first methods of interaction with the computer. It has a special charm - it creates a feeling of one-on-one communication with the machine without intermediaries. The command line is like an endless A4 sheet, on which the user enters text commands and gets the results in the form of text.

Graphical User Interface (GUI)

GUI is the most popular type of UI. This is a little window with different controls. Users interact with them using the keyboard, mouse and voice commands: click on the buttons, push the mouse, swipe a finger.

Gesture, voice, tactile, neural

"Any sufficiently advanced technology is indistinguishable from magic," the English science fiction writer and futurologist Arthur C. Clarke once said.

For example, through the Voice User Interface, you can give commands to your smartphone through voice assistants: Apple's Siri, Amazon's Alexa.

NUI (gesture, natural) is used in games for Xbox, Nintendo Wii or PlayStation consoles. You'll find the same technology in smart home equipment, such as turning on lights or adjusting the volume by changing the position of your hand.

Manufacturers are rocking the technology and expanding the capabilities of machines, and you can even enjoy new gadget tricks by sending your thoughts directly to your computer.

Graphic user interface

The UI of mobile and web applications, as well as games and services for entertainment, are more often referred to by this term.

Mobile interfaces

Is allocated in a separate group SIMP (Screen, Icon, Menu, Pointer). The approach to the design of mobile interfaces differs from the approach to the design of desktop applications. The user behavior when interacting with smartphones is different from on a computer because of the size of the screen and the lack of a separate keyboard with a mouse/touchpad. Elements here fill the screen completely, and blocks and systems depend on the requirements of the operating system.

The design of mobile applications also depends on the behavioral patterns of users, such as how they hold the smartphone in their hand, what actions are convenient to perform on the go, etc.

Web interfaces

The technology allows to create full-fledged web-applications, which are not inferior to desktop software in terms of functionality.

The advantage of such applications is that there is no need to install them on the computer - all the functions are available in the browser. Such applications are created using JavaScript, HTML and CSS.

Game and Material

It is connected with the mechanics of the gameplay. It is in it that the accompanying role of the interface is best revealed, because the player better feels that he is moving towards a goal (for example, to defeat the boss and pass the level). The interface depends on the game: buttons, gestures, mouse movements or interaction with the sensor on the screen or 3D interface in VR, pressing keys on the joystick.

The user interface model: the real world and the mental model of the user

Software products are designed to enhance our capabilities in the real world. Every product is like a superhero, its task is to help us with something: super memory, communication across all distances, maximum entertainment, and so on. All of these features we access through interfaces.

We unlock each application in a specific context. The context implies certain expectations of how things should work. Expectations are based on past experiences. When we encounter a new product, we unconsciously transfer to it formed expectations and habits that have been built in the past around another similar product (or way of solving a similar problem).

A mental model is a schema in our memory with the logic "object → interaction principle → result. In doing so, we expect similar behavior and result from all similar objects.

"The mental model is based on beliefs, not facts. This means taking what users already know (or think they know) about how your product works. And take that to work."

Stages of UI design - how to work out the UI

In international practice, the UI design approach has already become a standard. The UI design process includes the following key steps. In this block I rely on the materials of UX Mastery - a partner of Interaction Design Foundation, the world's largest UX design learning community.

• Strategy (Brand Strategy and UX Strategy) - defines a useful action, brand values and vision for the future. The strategy naturally influences the goals of the interface design project, the criteria for achieving the goals, and the priority of the project in the overall elevation landscape of the organization.
• Research (UX research) is the discovery phase. Comprehensive projects include extensive user research (UX research) and competitor analysis (benchmarking). Small organizations or startups can approach the research work in a simplified format and justify the idea built on the principles of minimum viability (Minimum Viable) through interviews, surveys and usability testing. It is in the research phase, according to the principles of design thinking, that the immersion into users' lifestyles, passions, goals and barriers takes place. Understanding the context of users helps to create socially relevant products that are highly likely to take root and start developing in the market: so they seem intuitive (mental models) and native (metaphors).
• Analysis (UX analytics) - the purpose of analysis is to draw conclusions from the data and give a confident start to the creation of design concepts. The conclusions are intended to help understand what's going on and start designing the interface.
• Interface design and prototyping - During the design phase, interface prototypes are created, tested by users and adjusted based on feedback. In this phase, prototypes with low-fi prototyping are used more often, as users focus only on the functions and are not distracted by the brand design (unique graphic identity) and other visual details.
• Interface design and Development - at this stage, an elaborate design is created, detailed content is written, all unique graphics are created and collaborative work with programmers begins.

The rules and principles of good interface design

The basic principles can be traced back through 24 years of interface research: from 1987 to 2009. These principles still work today.

Interface design guidelines. Schneiderman (1987) and Plaisent (2009):

• Strive for uniformity - design elements should be easy to recognize, even if the user has encountered your application for the first time. Create app user interfaces that are intuitive. For example, don't paint the start button red if it's green on most sites.
• Provide the same usability - for example, in the app and on the site, UI elements - menus and lists - should work the same way on every page.
• Provide informative feedback - an intuitive interface reacts instantly to user actions. The application should clearly show the current status on the screen: is payment expected, did the manager take the request to work, was the message delivered.
• Work out the closed solution flows - the users must clearly understand when they started a certain process and when they finished it. This principle is good in combination with visual statuses.
• Prevent errors - the ideal interface consists of tunnels through which users can instantly reach their goal. Aim for a point where users can't even make a mistake on their way to the goal. Even simple steps and statuses can go a long way at times.
• Provide an easy way to undo an action - no matter how clever the interface is, all users are human and they worry and make mistakes for different reasons. Have care messages ready in case something doesn't go according to plan. Or just give the option of a guaranteed cancellation of the action. This approach will help save attention, money, time and customer loyalty.
• Let the users feel that the control is in their hands: an intuitive user interface is like a spoon. You always know what to expect. Users understand that the interface is a machine and therefore expect complete control.  
• Minimize the burden on short-term memory - create an "everything at your fingertips" feeling. Then users won't feel like they've lost something, and they won't have a reason to worry that valuable information or work results need to be saved somewhere or remembered.