2. Design according to the seven principles of universal design

Keep these seven principles in mind when choosing and developing solutions:

• Equitable use: the product must be useful and marketable to all user groups. For example, a voice interface and a "hands-free" mode on a cell phone can be useful to many categories of users: people with vision problems, motor problems, able-bodied people whose hands are busy with another activity, group calls, etc.

• Flexibility or versatility: the product must satisfy a wide range of individual expectations and capabilities. The same phone must be usable in voice mode, in text mode, in silent mode, in hands-free mode, and so on. In this way, it adapts to different types of user, but also to different usage contexts for the same user.

• Simple and intuitive use: the product's use must be easy to understand,...