The Turing test is a hypothetical test to determine whether a computer system has reached the level of artificial intelligence. If the computer can fool a person into thinking it is another person, then it has artificial intelligence. Except in very narrow areas, no computer has passed the Turing test.
Free e-mail account providers such as Hotmail or Yahoo take advantage of this fact. They need to distinguish between new account registrations generated by a person and registrations generated by spammers' software. Why? Spammers burn through thousands of e-mail accounts to send millions of e-mails. To help them, spammers need automated tools to generate these accounts. Hotmail fights this practice by requiring registrants to enter correctly an alphanumeric code hidden within an image. Spammers' programs have trouble correctly reading the code, but most humans do not. With this reverse Turing test, also called a CAPTCHA, Hotmail can distinguish between a person and a program and allow only humans to register. As a result, spammers must look elsewhere for free accounts.
a. A side from those mentioned above, in what applications might businesses find it useful to distinguish between a human and a computer?
b. Describe a Turing test that a visually impaired person, but not a computer, might pass.
c. Search the Internet for the term CAPTCHA and describe its strengths and weaknesses.