What is universal interface design?

Universal design refers to designing interfaces for all people. This means that the interface design should be usable by everyone in any situation. Universal design doesn't only mean making the design accessible for people with disabilities; instead, it means designing the interface for all people inclusively.

For example, a dining chair doesn't follow a universal design because a child can't sit on it comfortably. Therefore, it excludes a group of people from using it. Such examples also apply to interface design. Thus, they should be designed universally to include all people.

Besides user limitations and disabilities, global inclusivity should be considered while designing universally. People may interpret the interface differently depending on cultural and linguistic norms. Therefore, a universal design should be adopted which is usable by everyone.

Principles of universal design

There are seven principles of universal design which apply not only to interface design but also to industrial and architectural design. These principles are listed below:

Equitable use

The principle of fair use says that the design should be usable and marketable for all people with varying abilities. This means that no group of users should be excluded from using the design. Otherwise, the design will not be inclusive, and users will feel stigmatized. When identical use is impossible for all, an equivalent experience should be provided. For example, a user interface should use colors and symbols to cater to color-blind people.

Flexibility in use

The design should allow a range of choices to act. This means that the user should be able to choose a method according to their preference. Moreover, the design should adapt to the user's pace and precision. For example, many systems allow users to adjust a cursor's speed according to their preference.

Simple and intuitive to use

The design should be easily understandable by people independent of their knowledge, experience, or concentration level. This is implemented in interface design by providing appropriate feedback at every step and allowing the user to navigate intuitively.

Perceptible information

This principle states that the information displayed in the design should be communicated effectively, regardless of the user's environmental conditions and physical limitations. This is implemented by using a range of options for conveying information. For example, an error message should be displayed using text, symbols, as well as sound.

Tolerance for error

The design should avoid erroneous actions and minimize the consequences of an unintended activity. Critical steps, which can produce errors, should be kept hard to reach. In case of an error, the option to undo should be provided. For example, an interface should shield the delete option and ask for confirmation before deleting.

Low physical effort

This principle calls for comfortable use of the design with minimum effort. In interface design, this can be implemented by reducing the user's need to move the cursor and scroll. For example, the navigation options must be attached to the screen, so the user does not have to scroll to the top every time.

Size and space for approach and use

The design should allow users to reach for the elements comfortably, regardless of the person's height, posture, or position. In interface design, the size of the features on a screen should be appropriate enough for a user to select them conveniently. For example, the buttons on a bigger screen should be large enough to be visible and not overlooked by the user.