Earlier this year, Turing Award -winning computer scientist Jim Gray set out on a short sailing trip. He did not return. As search parties tried unsuccessfully to find him, the effort was taken online.

News spread like wildfire, with some of West Coasts smartest people aiding the effort. An imaging satellite was routed to the Pacific route Gray had been on, in response to requests by Google and NASA. Time was urgent, and the satellite has thousands of images. With these two issues in mind, Amazon offered their form of help: they put the data on the Turk.

Amazon Mechanical Turk is a service launched in 2005 as a solution to tasks too difficult or impossible for computers to achieve. Billed as the Artificial Artificial Intelligence, the Turk offers an infrastructure for paid crowdsourcing. A requester is given a simple interface for splitting up the work into smaller tasks, called HITs. The HITs are given a value and posted on the site, where the Turk’s userbase is given the option to accept the HITs or ignore it. Successful completion gives the user monetary credit, which can then be transferred to Amazon credit or simply to a bank account.

In the search for Jim Gray, volunteer Turk workers examined images from the satellite. They were given reference of what his yacht would look like, and photo by photo, they marked whether there was anything unusual in the photos. Each photo was reassessed a number of times.

Photo semantics analysis is a prime use for crowdsourcing. Since it’s inception, Mechanical Turk has hosted many similarly clever projects. Computers have limits, and the theory under which Mechanical Turk was conceived, to create a human-intelligence powered computer, has been the guiding light to its most successful projects. I’ll revisit some of best examples in the future. Of course, the service has also been exploited for less than saintly purposes, something that I will also return to.

Unfortunately, the Jim Gray story did not yield a happy ending. Yet, technology’s ability to mobilize such a large group of eager but physically unable volunteers makes our future seem all the more hopeful.

For more information on Amazon Mechanical Turk, see Mechanical Turk on Wikipedia and the Mechanical Turk FAQ page.