Are you human? by Aram Bartholl…
CAPTCHA is the acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart” and was developed in 2000 by information scientists at the Carnegie Mellon University. Web-based services such as Yahoo require users to recognize and type a randomly generated series of letters or numbers which appear on the screen as a CAPTCHA image. This test is designed to ensure that a web form is not being completed by the automatic scripts used by spammers.
In the classic Turing Test a person distinguishes between a computer and a human. CAPTCHA Codes turn this idea around. Based on the input of a correct or incorrect response, the software decides whether it is dealing with a real person or an automatic script. CAPTCHA Codes are publicly available, and each code is uniquely generated by a computer program which “knows” the correct response, although it can not itself “read” the code. (via)
