1. A method utilizing a CAPTCHA to generate a human likeness score, the CAPTCHA provided through a graphical interface, the method comprising blocks: a) receiving a user solution to the CAPTCHA; b) receiving a user interaction pattern descriptive of an interaction undertaken by the user, through the graphical interface, to achieve the user solution; c) determining the accuracy of the user solution; d) comparing the user interaction pattern against an interaction model generated from interaction patterns of previous users; e) calculating the human likeness score based upon the determination in block c) and the comparison in block d), wherein the human likeness score lies within a continuum of human likeness scores.