Friday, February 24, 2006

Mechanical Turk - A Grid of People Grid computing meets Wetware ...

In 1769, Hungarian nobleman Wolfgang von Kempelen astonished Europe by building a mechanical chess-playing automaton that defeated nearly every opponent it faced. A life-sized wooden mannequin, adorned with a fur-trimmed robe and a turban, Kempelen’s "Turk" was seated behind a cabinet and toured Europe confounding such brilliant challengers as Benjamin Franklin and Napoleon Bonaparte. To persuade skeptical audiences, Kempelen would slide open the cabinet’s doors to reveal the intricate set of gears, cogs and springs that powered his invention. He convinced them that he had built a machine that made decisions using artificial intelligence. What they did not know was the secret behind the Mechanical Turk: a human chess master cleverly concealed inside.

Today, we build complex software applications based on the things computers do well, such as storing and retrieving large amounts of information or rapidly performing calculations. However, humans still significantly outperform the most powerful computers at completing such simple tasks as identifying objects in photographs—something children can do even before they learn to speak.

When we think of interfaces between human beings and computers, we usually assume that the human being is the one requesting that a task be completed, and the computer is completing the task and providing the results. What if this process were reversed and a computer program could ask a human being to perform a task and return the results? What if it could coordinate many human beings to perform a task?

Amazon Mechanical Turk provides a web services API for computers to integrate "artificial, artificial intelligence" directly into their processing by making requests of humans. Developers use the Amazon Mechanical Turk web service to submit tasks to the Amazon Mechanical Turk web site, approve completed tasks, and incorporate the answers into their software applications. To the application, the transaction looks very much like any remote procedure call: the application sends the request, and the service returns the results. Behind the scenes, a network of humans fuels this artificial, artificial intelligence by coming to the web site, searching for and completing tasks, and receiving payment for their work.

All software developers need to do is write normal code. The pseudo-code below illustrates how simple this can be.

read (photo);
photoContainsHuman = callMechanicalTurk(photo);
if (photoContainsHuman == TRUE) {
else {