Interaction Machine Theory is a vital field of research in Computer Science. First characterized by Alan Turing as the "Choice Machine" in distinction from his famous "Tape Machine", Interaction Machine Theory has been formalized much more recently (1996) by Peter Wegner and Dina Goldin.

Interaction is more powerful than Algorithms because an interactive calculator with buttons for numbers and operations is more powerful than an "opaque box" with buttons for a fixed set of computations (i.e. "2+2"). The user in an interactive process performs work. Algorithms can describe this work, and the user can build algorithms, but algorithms are not interactive.

As the premise for Design and Engineering, this theory tells us that the user interface represents actions and results as half of the whole system. This means different things in different applications, so it's hard to get more specific, but the implication tends to change the way systems are engineered to be more interactive and more flexible. Think "tools" more than "processes", as if "tools are more powerful than processes" like "interaction is more powerful than algorithms".

Saturday January 12, 2008