Turing tests

test of a machine's ability to exhibit intelligent behaviour equivalent to, or indistinguishable from, that of a human

upright=1.35|thumb|This CAPTCHA (GIMPY-R, c. 2005) of "smwm" obscures its message from computer interpretation by twisting the letters and adding a slight background color gradient.

reCAPTCHA Inc. is a corporation owned by its parent company Google, which produces the CAPTCHA system. It serves to web hosts to distinguish between human and automated access to websites. The original version asked users to decipher hard-to-read text or match images. Version 2 also asked users to decipher text or match images if the analysis of cookies and canvas rendering suggested the page was being downloaded automatically. Since version 3, reCAPTCHA will never interrupt users and is intended to run automatically when users load pages or click buttons.

1950 article by Alan Turing on artificial intelligence that introduced the Turing test

test of machine intelligence