A person is literate who can with understanding both read and write a short simple statement on his or her everyday life, and can apply this knowledge to function in a textual environment.
799 million people are illiterate. Illiteracy can be found anywhere, including London, New York and Tokyo. In addition, there are many people who are using devices that do not support their native language.
Mobile devices that were designed with a Western audience in mind are increasingly used in places like Africa and India with much lower levels of structured learning.
Design research, as the only tool that can really address this problem, reveals a number of interesting insights that designers can act upon.