It is very important to design the system for users considering human abilities and requirements. But people have different abilities, weaknesses, they come from different backgrounds and cultures, they have different interests, viewpoints, experiences, ages, and sizes. So we should consider all these facts when designing an interactive system.
Universal design is the process of designing products so that they can be used by as many people as possible in as many situations as possible.
The universal design may seem like a huge task, but it should not become complex or costly. There are seven universal design principles.
No user should be excluded, access to the system should be available to users with any abilities.
The design should allow for a range of abilities and preferences to adapt to the user's pace.
Simple and intuitive
The system should be simple regardless of the knowledge, experience, language, or level of concentration of the user.
The design should provide effective communication of information regardless of the environmental conditions or the user’s abilities.
Tolerance for error
The system should be designed to minimize the impact and damage caused by mistakes or unintended behavior.
Low physical effort
The system should be designed to be comfortable to use, minimizing physical effort and fatigue.
Size and space for approach and use
The placement of the system should be such that it can be reached and used by any user regardless of body size, posture, or mobility.
According to universal design principles, providing access through more than one mode of interaction is important. So good universal design relies on multi-modal interaction.
- Sound in the interface
Sound is an important contributor to usability. There is experimental evidence to suggest that the addition of audio confirmation of modes, in the form of changes in keyclicks, reduces errors. Sound can convey transient information and does not take up screen space, making it potentially useful for mobile applications.
- Touch in the interface
The use of touch in the interface is known as haptic interaction. but it can be roughly divided into two areas: cutaneous perception, which is concerned with tactile sensations through the skin; and kinesthetics, which is the perception of movement and position. Both are useful in interaction but they require different technologies.
- Handwriting recognition
This is a very natural form of communication like speech. With handwriting recognition, we can input both textual and graphical input using the same tool. There were problems with the use of handwriting as an input medium. however, there are several mechanisms to capture handwriting.
- Gesture recognition
Being able to control the computer with certain movements of the hand would be advantageous in many situations where there is no possibility of typing, or when other senses are fully occupied. It could also support communication for people who have hearing loss, if signing could be translated into speech or vice versa. But, like speech, the gesture is user-dependent, subject to variation, and co-articulation. The technology for capturing gestures is expensive.
Interactive systems are usually designed to cater to the average user, but unfortunately, this may exclude people who are not average. People are diverse and there are many factors that must be taken into account if we are to come close to universal design.
- Designing for users with disabilities
It is estimated that at least 10% of the population of every country has a disability that will affect interaction with computers. Using screen readers, gesture input, voice recognition we can provide access to the system to people even has disabilities.
- Designing for different age groups
In society, we can see older people and children have specific needs when it comes to interactive technology. Goals, likes, and dislikes have differed when we compare adults and children.
- Designing for cultural differences
Cultural difference is often used synonymously with national differences but this is too simplistic. Whilst there are clearly important national cultural differences, such as age, gender, race, sexuality, class, religion, and political persuasion, may all influence an individual’s response to a system.