This is a summary of Dix et al chapter 10(which can be found here).
Chapter 10 speaks about universal design which is about designing systems so that they can be used by anyone in any circumstance. It also speaks about multi-modal systems which use more than one human input channel in the interaction e.g. speech, non-speech sound, touch, handwriting, gestures.
There are seven proposed general principles of design.
- Equitable use: the design is useful to people with a range of abilities and appealing to all. No user is stigmatized or excluded. Wherever possible, access should be the same for all; where identical use is not possible, equivalent use should be supported.
- Flexibility in use: the design allows for a range of ability and preference, through choice of methods of use and additivity to the user’s pace, precision and custom.
- System should be simple and intuitive to use regardless of the knowledge, experience, language or level of concentration of the user.
- Perceptible information: the design should provide effective communication of information regardless of the environmental conditions or the user’s ability.
- Tolerance for error: minimizing the impact and damage caused by mistakes or unintended behavior.
- Low physical effort: systems should be designed to be comfortable to use, minimizing physical effort and fatigue
- Size and space for approach and user: the placement of the system should be such that it can be reached by any user regardless of body size, posture or mobility.
The concept of universal design is a good one. By knowing your users, you are able to create a system that is not only easy to understand and require little effort from the user while providing flexibility but you also ensure that the system is accessible to all users through all range of abilities. This the goal which human centered computing seeks to achieve.
This system may sound impossible to achieve and that is because it is. Creating a Universal design is possible with a limited set of users who’s characteristics won’t extend pass a certain threshold. Unfortunately, I do not believe that on a large scale, any system will be able to fulfill all the requirements suggested and be truly universal.