Time, presence and physical attentiveness are our most basic proxies for something ultimately unprovable: that we are understood.

Above all, the translation of books into digital formats means the destruction of boundaries. Bound, printed texts are discrete objects: immutable, individual, lendable, cut off from the world.

If computers remain far worse than us at image recognition, a certain over-confident combination of man and machine can elsewhere take inaccuracy to a whole new level.

Time, presence and physical attentiveness are our most basic proxies for something ultimately unprovable: that we are understood.

From exam grading to health education to professional training to democratic participation, paths towards self-realization and success in the world are often daunting and obscure: journeys only the privileged feel confident setting off along.

I spoke at TED Global 2010 about the ways that video games engage the brain, and in particular, the idea of reward structures: how a challenge or task can be broken down and presented to make it as engaging as possible.