Designing an intuitive user interface

What is UI design?

The term UI, or User Interface, translates as " userinterface ". According to Dario Calonaci, user interfaces are everywhere, from books and remote controls to voice and language. He writes "When you're interacting with something, when you're looking for something, [...] you're almost always doing it through a user interface, or something that can be extended to its definition." The user thus refers to the person doing the action.

And what is an interface in computer language? 

The definition of this word has been fixed as "the junction between two pieces of hardware or software enabling them to exchange information by adopting common physical or logical rules" by the French Academy. In other words, the user interface is the place where human and machine communicate and exchange information. For the purposes of this article, the term UI will refer to this definition.

An interface must enable users to perform the action they want easily, efficiently and quickly. There are several rules to facilitate their design.

Ben Shneiderman's eight golden rules of interface design

Ben Shneiderman, a professor at the University of Maryland, has laid down several golden rules for interface design. These are formulated in general terms, and need to be adapted according to the context to which they are applied. Their primary aim is to enhance user productivity.

• Coherence

Similar situations should be governed by consistent sequences of actions. For example, the same terminology should be used in prompts, menus and help pages, while colors, display, fonts and typefaces should be consistent. Exceptions, such as confirmation or deletion messages and incorrect password alerts, must be understandable and in limited characters.

• Universal ergonomics

The interface must take into account the diversity of users and their needs : level of proficiency, age, disability, nationality and technological diversity. These elements enrich the requirements that guide the design. Adding specific features for novices, such as more detailed explanations, and for experts, such as shortcuts, enhances the quality of an interface.

• Feedback

Feedback can be short for frequent or non-essential actions, but should be more substantial for unusual or major actions. Its presence allows the user to understand that his action has been taken into account.

• Designing logical, finite interactions

Action sequences should be organized with a beginning, middle and end. Notifying the user that they have completed the action provides a sense of satisfaction, relief, and signals that they can prepare for the next sequence of actions. For example, action sequences on e-commerce sites begin with product selection, and end with purchase confirmation. 

• Error prevention

Interface design should ensure that the user makes as few major errors as possible. What's more, if the user does make a mistake, the interface must allow him to fix it in a simple way, by telling him how.

• Reversibility

Actions must be reversible. This allows the user not to fear using the interface, or exploring it. Reversibility must be made simple. 

• User interface control

Users like to feel that they are in control of the interface and that it responds to their actions. Sudden changes or unusual interactions are therefore to be avoided. The interface should not force the user to enter data, laboriously search for information, or fail to deliver the desired result.

• Memory

Humans have limited memory capacities. Short-term memory requires that the information contained in interfaces is not too voluminous, and does not have to be memorized from one screen to the next. 

Why design a user-friendly interface?

Creating a pleasant, unforgettable user experience 

UI design determines the perceived quality of a website, software or application by the user. The design of an interface cannot be haphazard, but must respect a certain number of criteria based on pre-established objectives . These include : 

• Design an optimal user path,
• Reduce the number of clicks required to access the information you're looking for,
• Offer customers a new experience,
• To positively stand out from the competition.

To measure the perceived quality of a user interface, several indicators can be examined: bounce rate, average time per session, number of pages viewed per session, or number of visits. 

Identifying a user's needs and expectations is a complex task. Fortunately, several tools exist, such as the empathy map designed by XPLANE. It allows you to schematize what a user sees, thinks, feels, says, does or hears. It also encourages users to question their identity and needs. All this information is invaluable in understanding the user, his motivations or even his obstacles.

Including all users: digital accessibility in UI design

One of Ben Shneiderman's eight golden rules is universal usability. However, many interfaces do not take digital accessibility into account. 

Digital accessibility means enabling people with disabilities to use an interface and making it comprehensible. 

The French government has issued a number of criteria toassess the accessibility of an interface. These include the inclusion of alternative text in image metadata, the presence of a heading for each link, and the fact that no new window opens without user action.

The W3C website also provides a list of tools and recommendations for ensuring that a website complies with accessibility standards. Performing these audits is essential for proposing inclusive interfaces. Accessibilitychecker.org also makes it possible to obtain an audit almost instantaneously, and to identify where a website could be improved in terms of accessibility.