Lecture at the ICOGRADA/FRONTEIRAS congress, Sao Paulo, April 29th and 30th, 2004 – “Structure is an important way to start: structure information in ways that make it accessible to others: facilitating access is like giving out a passport: if designers help their users to cross frontiers of cultural knowledge and experience, and facilitate them to exchange and share information and experiences with others, then design has answered its first and most important brief: to build interfaces.” (Max Bruinsma)