The private reflective self created by reading differs profoundly from the un-selfconscious social role played by participants in a culture that knows no writing. Literacy allows us to see human society in formal terms that are denied to an oral culture that only plays out its drama. The oral and written ways of being in the world have contended rancorously throughout Western history, the rancour being driven more often than not by literate prejudice against the oral rules. Now the great gulf in communication and in cultural organisation that was opened up by unchanging letters on a static surface promises to be healed by a new kind of literacy, one that orchestrates these differences in a signal at the same time more energising and more irenic than the literacy of print. In the world of print, the idea and its expression are virtually one.
Digital literacy works in an inherently different way.
The same digital code that expresses words and numbers can, if the parameters of expression are adjusted, generate sounds and images. This parametric variation stands at the centre of digital expressivity, a role it could never play in print. The multiple facets of this digital signal constitute the core difference between the two media, which our efforts in data visualisation and sonification have scarcely begun to explore. If we think of the institutional practices built on the separation of words, image and sound, such as separate departments for literature, art and music, we can glimpse the profound changes that will come when we put them back together. To be deeply literate in the digital world means being skilled at deciphering complex images and sounds as well as the syntactical subtleties of words.