"The world's people, and the connections among us, provide the raw material for cognitive surplus. The technology will continue to improve, and the population will continue to grow, but change in the direction of more participation has already happened. What matters most now is our imaginations. The opportunity before us, individually and collectively, is enormous; what we do with it will be determined largely by how well we are able to imagine and reward public creativity, participation, and sharing.

"For those of us over forty, exercising this kind of imagination requires conscious effort, because it's so different from what we grew up with. At NYU, where I teach, I get to see the world through my students' eyes by listening to them talk, reading what they write, and watching what they do. This gives me some sense of the world as twenty-five-year-olds see it, and it looks very different from (and mostly better than) the world I grew up in. But the potential for really radical change may be even better illustrated through the eyes of children.

"I was having dinner with a group of friends, talking about our kids, and one of them told a story about watching a DVD with his four-year-old daughter. In the middle of the movie, apropos of nothing, she jumped up off the couch and ran around behind the screen. My friend thought she wanted to see if the people in the movie were really back there. But that wasn't what she was up to. She started rooting around in the cables behind the screen. Her dad asked, 'What you doing?' And she stuck her head out from behind the screen and said, 'Looking for the mouse.'

"Here's something four-year-olds know: a screen without a mouse is missing something. Here's something else they know: media that's targeted at you but doesn't include you may not be worth sitting still for. Those things make me believe that the kind of participation we're seeing today, in a relative handful of examples, is going to spread everywhere and to become the backbone of assumptions about how our culture should work. Four-year-olds, old enough to start absorbing the culture they live in but with little awareness of its antecedents, will not have to waste their time later trying to unlearn the lessons of a childhood spent watching Gilligan's Island. They will just assume that media includes the possibilities of consuming, producing, and sharing side by side, and that those possibilities are open to everyone. How else would you do it?

"The girl's explanation has become my motto for what we might imagine from our newly connected world: we're looking for the mouse. We look everywhere a reader or a viewer or a patient or a citizen has been locked out of creating and sharing, or has been served up passive or canned experience, and we're asking. If we carve out a little bit of the cognitive surplus and deploy it here, could we make a good thing happen? I'm betting the answer is yes, or could be yes, if we give one another the opportunity to participate and reward one another for trying."