Chris Crawford defines interaction using a conversational paradigm – two parties (at least) are involved, each party takes it in turns to listen, think and speak. The process is iterative – conversations (or more broadly, experiences) are built through the repetition of this schema. Crawford also leaves room for an analogue gradient of ‘interactivity’: a play in which the actors respond to the energy and reactions of the audience rates a 0.1 on the Crawford Scale. He does not give an example of a 10, but I suppose it would be something like an MMORPG, where the entire content is designed to be reactive to the users and nothing at all happens until they start the ‘conversation’ by performing an action.

Come to think of it, a conversation would rate a 10 as well. Interaction, in short, is communication.

We are asked to define physical interaction. Not to be pedantic, but is there any other kind? All communication is transduction – it is a transfer of encoded energy which must progress through the physical world. Even the most disembodied communication imaginable – maybe via an implanted device that decodes the electrical impulses within the language centers of its wearer and sends them wirelessly to a similar device in another brain – must perform the physical action of transduction. Both users may be paralyzed, but by definition, if one is proposing to bypass the physical world, one is invoking the supernatural. And I don’t believe in that.

If all interaction is physical interaction, then ‘good physical interaction’ just means ‘good interaction’. Which is fine by me, I like Chris Crawford’s definition. But ‘good’ is a matter of taste. (And this is very much a separate axis from the ‘interactivity’ axis mentioned above; something may be good but not very interactive, or highly interactive but not good.) So this question just asks what I like. At MOMA I liked:

• Synesthesia: Projects which transduce or associate two different forms of sensory experience. Like Squiggle, an iPad app that allows you to draw colored lines that become virtual strings that you can then pluck for music.
• Sensory Extension: Not highly interactive, but highly interesting as a vehicle for extending one’s experience of the physical world. (I forget the title… the optical clothing that was made for children to allow them to explore grass from an ant’s-eye perspective).
• Hidden or Unintentional or Untargeted Interaction: Also not strictly interactive by Crawford’s definition, but see below. I am very intrigued by the idea of interactions that employ unwitting third parties as mediators. So the yellow legal pad, which had micro-printed lines with the names of Iraqis killed in the Gulf War, and intended to be disseminated into government circles where it might be used and archived unwittingly, or discovered in the course of use, was brilliant.

• Objects which interact with each other: The Cubelets and Sifteo Cubes. This also stretches Crawford’s definition because the human user is modifying the interaction of the cubes with each other. (Though in a sense the same thing can be said for any computer program that uses Object-Oriented Programming; but we experience that as a seamless whole.)

• Experiences which blur the boundaries between real and virtual worlds: I just loved the Avatar Suit. I love how its users tended to altered their gait when wearing it, to look more like a virtual game character. And the cube table with virtual shadows (including shadows of trees and people who weren’t there, was wonderful.

Many exhibits at the show (maybe even most) were not interactive by Crawford’s definition, but were interesting even so because they facilitated unusual experiences by users in reference to the physical or social worlds.

I’m going to get a little metaphysical here. Because I think in a certain sense Crawford’s definition is too specific. I think the reason interactivity is so fascinating to people is because that is a fundamental feature not just of the human world but of the natural world as well. We evolved as hunter-gatherers, and a great part of our success as a species relies on our ability to predict how the external environment will respond to our actions. If we move quietly, and stand downwind, the stag won’t detect us until we are close enough for an arrow shot. The world itself is always “Talking to Us.”

A word Crawford used in his definition clicked a lot of related buttons for me: he said interaction is iterative. What else is iterative? The Scientific Method. Evolution. The construction of a body through continual cell division and differentiation. Iteration is a key component in the process that builds complexity. Is there really such a huge difference between a “conversation” with a person, with an animal, with a collection of physical objects and with a digital machine that was built to respond to us?