Accesibility in UX Design

The accessibility of an information system aims to ensure that it can be used by all types of users. Usability covers a set of concepts relating to its execution time, performance, ease of learning, and user satisfaction. The concept of user experience goes a step further, considering that it is based on “an emotional state”.

The ISO 9241-11 standard, relating to the ergonomics of human-system interactions defines the usability of a system as “the extent to which a product (or service or an environment) can be used by users to achieve objectives. Specified with effectiveness, efficiency, and satisfaction in a specified (particular) context of use “. To specify or measure usability, it is necessary to identify the objectives; to break down the concepts of effectiveness (accuracy and completeness), efficiency (resources necessary to achieve the expected result, whether human, temporal, or material), and satisfaction (comfort, acceptability); and define the components of the context of use in such a way as to endow them with measurable and verifiable attributes.

The concept of efficiency as targeted by the ISO 9241-11 standard implies taking into account error prevention and risk management. The user-friendliness of a system is considered in terms of its ease of learning, regular use, accessibility, and ease of maintenance. The context of use is a combination of users, goals, tasks, resources, and environment that can influence usability.

The ISO 9241-210 standard, relating to the ergonomics of computer systems, considers the concept of accessibility as the capacity of a system to be able to be used by all types of users. This presupposes a design centered on the human operator, taking into account their needs and experiences. It defines user experience as “the perceptions and reactions of a person that result from the actual and/or anticipated use of a product, system or service”.

Also, the concept of user experience (UX) goes beyond the objective measures underlying that of usability, by including a hedonic and therefore subjective dimension. This appeals to the emotional state of the users. As opposed to the perception of effectiveness, efficiency, and satisfaction as representations of collective responses of a group of users, UX is centered on an individual’s experience, preferences, perceptions, and feelings before, during, and after use.

UX can be as much about a personal user experience as it is about design devices to achieve an optimal experience. A user-oriented design aims to achieve the objectives of UX: in this sense, an iterative design process, centered on the user by including him in the process is a first way of approaching the question to achieve the expected results.

UX is at the center of web interface design and is often opposed to UI (user interface) whose aesthetic goals do not always meet those of practicality and usability of UX. However, the key to a successful web interface will combine these two concepts, which must be considered in a complementary way, as well as that of accessibility which corresponds to the rules for optimal use of a web page. These relate to readability, navigation, and all the functionalities implemented. By extension, it refers to the optimization of a web page for people with visual or hearing disabilities. For the user, these three elements are inseparable and their optimization contributes to optimal comfort.